Internet and Technology

If you are a computer enthusiast, you don’t need to be told about the most common computer problems. However, a majority of people who own a computer don’t understand that there are common computer errors that you will begin to experience as your system ages with time. It does not necessarily mean that you should abandon your old PC and look out for buying a new one. On the other hand, it would be best if you gain knowledge about these problems and then find out how to troubleshoot them.

Computer Hangs-Up: You must have seen your computer hanging up. At times, it would have been impossible for you to even get the cursor moved. You should leave the computer for a while and give it some time to do its thing on its own and then you can get back online to finish what you need to do. If it does not come to a normal working condition in few minutes, try rebooting your system. It is not recommended that you do this all the time; however sometimes this is the only way to bring it back to life.

Maintenance problem: Unfortunately, over 75% of computer users don’t realize the need to take proper acre of their systems. Poor PC maintenance can lead to nasty technical errors which will keep coming up every now and then, thereby disturbing you in the middle of the work.

Blue Screen Error: This is one of the most complicated computer problems. It would make your system just freeze up or even worse the screen would turn totally blue. It could mean that your machine has a short circuit or it could have acquired a computer virus.

No matter what types of computer problems you are facing, you can get them troubleshoot by computer experts. You can nowadays find a lot of such professionals on the Internet. Such services are known as online computer support. The techs will also offer you valuable information on how to properly maintain your PC.

These resources are available for 24×7 and make sure that your problem gets resolved quickly and you get quality services at the most reasonable rates.

To start the most significant fact that should be stated is that the computer is a tool, and as with any educational tool, from books to crayons, it can be used to enhance the curriculum and promote learning, but it can also be misused and abused. In this essay, I will discuss the disadvantages of having computers in the classrooms due to the misuse and the abuse of this tool.

I found it hard to find research that had been done on this topic because not only is the research on the effectiveness of computers in the classroom scarce but the research that is there is often done by software companies and therefore may be biased. (Emmans 2001). Even though there is no clear-cut answer to the question of a computer being a friend or foe in the classroom, having an unsolvable question of good or bad brings many issues to light. For example, the fact that much of the software designed for children is appealing to them. If nothing else, it at least holds the children’s attention. Though this may seem like a positive characteristic, consider this, just because a television show holds your attention, does it necessarily educate you? The answer to this is simple, maybe some do, but certainly not all do, mostly they are just simply entertaining. This causes me to raise an eyebrow at some, not all, software. As a teacher, one must not use time-fillers, cause a child can watch television or play on a computer at home, but as a teacher, we must educate, and if there is no educational value in the software, what good is it for a teacher? On the defense for teachers, another reason for computers being a shortcoming is that sometimes the software is not obvious that it is non-educational. This can be a common mistake of any educator, being fooled that a product could be educational when it is merely entertainment software dressed up in an educational costume aimed at these gullible teachers.

According to Cindy C. Emmans (2001), a professor of Educational Technology at Central Washington University, on software in the classroom…

” Often feedback is the key to learning, and computers are appealing because this feedback can be immediate, which is of course a very effective learning tool. Unfortunately, this feedback is not often as effective as it might be, perhaps because it is not easy to return to the original question to try again, or the student must begin at the beginning to review the original content rather then backing up a step or two. In some cases, the feedback for the wrong answers is more appealing than that for the right answer, causing students to try and get the wrong answer simply for the entertainment value”.

Gerald W. Bracey sums it up adequately in a journal article called Principal by basically saying that the bells and whistles are all there, but the education is not, because it was not produced by someone who understands how children learn. (1996, p.6).

More arguments in the research area continued in September of 2000, the Alliance for Childhood published a statement against the use of computers in schools. More than 85 experts in various fields including psychiatry, education, and philosophy signed the statement in which calls for a suspension on the promoting introduction of computers into the nation’s elementary schools until there is a more careful assessment of their effect (Hafner, 2000). Another influence in opposition to computers in classrooms is that of Jane Healy, an educational psychologist and the author of “Failure to Connect,” a book criticizing educational applications of computers. Thomas Crampton interviewed Mrs. Healy and she declared that computers “can hurt children’s personal skills, work habits concentration, motivation, (and) the development of social skills” (IHT, October 2000, p. 19).

Another reason that computers in the classroom would prove to be a disadvantage is the availability of computers in the classroom to each individual student. It is rare to find a school that, in each classroom, has a computer supplied for each student. This then brings up the problem of scheduling and rotating the students to the computers available. (Tiene 2001) This begins a whole new ball game in which you are now consuming a lot of time in which could be used for more productive measures rather then scheduling computer time for each student. If this is the case, and only a specific amount of students can be on the computer at one time, then you are dividing your classroom, and not integrating it, as it should be. This causes many difficulties in teaching a whole group instruction, which leads to problems in skill development, since the attention of some students is lacking. (Tiene 2001).
On the Colorado state education web site (2003), I was able to find questions that were asked to teachers regarding computers in their classrooms. The teachers were asked, “What do you find unattractive about teaching in a computer based classroom?” The one teacher commented that, ” Students have a tendency to come in a print out their papers at the beginning of class instead of coming into class with a hard copy…” Another teacher said, ” Technological difficulty, your whole lesson could be shot for the day if the computer would go down”. When the teachers were asked about the difficulties they faced themselves and with the students due to computers in the classroom, they answered, ” It is hard to get the students attention when they are on the computers.” Another teacher commented, ” There are times that I send them to work and instead they are interacting with each other.” Another teacher stated her fear of the computer classroom by saying that, ” Students are at their own screens, they’re in their own little world, and they are not talking to their classmates, sometimes I think that they don’t even know half the names of all the people in their class.” (Barnes 2003) I feel that these teachers comments are very important when looking at the issue of computers in the classrooms, because these are the people that actually interact with the children in the classroom, they are not just some random research study by a software company, these people are the real thing, and they see how computers are effecting their classrooms.

Another issue of computers in the classrooms regards the child’s health. If a child were to be functioning on a computer for a long interlude of time or with incorrect positioning they will inadvertently obstruct their own health, some problems caused from this include muscular-skeletal injuries and vision problems. (MacArthur & Shneiderman, 1986).

Another issue concerning computer use in classrooms is that a lot of teachers have not been trained to use a computer, and many do not know how. An enormous amount of time would have to be consumed for the teachers to learn both the hardware and the software of the computer. They also would need time to collaborate with other teachers. Time is something that many teachers spend planning lessons and the weekly events of their classroom. The other problem that was just mentioned was the training of the teachers. Some educators do not have local training options available to them. Some do not have the time or money to spend on it. Another issue is that even if a teacher does go through training, there are always unsuspected things that can go wrong with a computer. If a teacher were to base their whole lesson on a computer, and it were to crash, and the teacher just being minimally skilled in using computers, would not be able to fix the system so that they could continue their lesson. (Tiene 2001).Therefore an on-site technology expert would be needed on site at all times in case any of these incidences would happen, and quite frankly I do not think that there are too many school districts looking for another expense.
Another reason for computers being a disadvantage in the classroom is that if the computer is Internet accessible, if this is the case, then the children can be exposed to Internet content that is not appropriate for their age level. They can also be exposed to child predators, which is a huge concern in today’s world.
Though this may seem far-fetched it truly is not in an article published on the gurdian angel websitein 2000 states,
“The facts are plain. Children are being targeted, solicited, and made victims by pedophiles. What do the ratios or statistics matter? Isn’t even one too many? These predators range from the simple minded closet pedophile who has surfaced because they believe they are safely anonymous behind their account alias, to the highly organized and skilled child pornography rings that operate predominantly off of US soil, behind quick discard web sites, and anonymous re-mailers, pushing their hideous wares for big profits. Have you ever heard of a child being molested or kidnapped in your hometown? Don’t you teach your kids to watch for certain things and, not to talk to, or go anywhere with, strangers for just that reason? This is our point. Just as there are real world lessons that you teach your children, there is a necessity to teach them cyber-world lessons. ” (Hook, 2000).
To put this quite simply, are you sure that your child is being watched very closely when accessing the Internet at school? It sure would be hard for one teacher to keep a close eye on each individual student in the classroom when they are all accessing the Internet at the same time. Therefore are you, as a parent or a teacher, really quite sure that a computer is necessary to learn in school? I mean, didn’t you, the parent or teacher, learn in school without the computer? I agree that learning the latest technology is a necessity, but I do not agree with using computers for classes like mathematics or reading.
To sum it all up, Computers in the classroom lacks research of it being an advantage in the classroom. Computers in the classroom may not provide the students with the proper education that they need if the software being used is not adequate. Computers may not be, depending on the school, made available to each student. The attention of the students is harder to get when they are on the computer. An inexperienced teacher in the technology area may cause many problems in the classroom, and consume valuable time that could be used to educate. Most schools do not provide an on site technician in case a difficulty may arise. The children’s health may be affected by long-term use of the computers, and probably the most frightening one is that these children can be exposed to child predators and unfiltered inappropriate content through the web while they are in school and in their classrooms presumed to be receiving their education.

It attacks your computer like the South American army ant. Tiny, harmless looking critters by themselves, in larger numbers they can cover, kill and dissolve a full grown cow in a matter of hours.

Okay, maybe not exactly like that. But, wood shop and machine shop owners are experiencing the devastating effect manufacturing dust can have inside their shop computers. And they are looking for answers.

It doesn’t take much to ruin your day, especially, when metallic dust meets sensitive electronic components. Electricity chooses to travel in the shortest route possible, and little bridges of metal dust make great short cuts. Zap! WRRrrrrrr…

And wood dust makes a great insulating blanket. That’s okay if you’re lost in a big wood bin and freezing to death, but to a hard working computer it can be bad news. Heat sinks and fans attempt to dissipate the heat from within your computer, but a layer of dust can reduce or prevent this transfer of heat. Also, computer fans can malfunction when dust and grime are allowed to build up. Things heat up. Computers die. Data is lost. Business suffers.

Okay, what’s the answer then? How do you protect your computer from dust?

The actions you are willing and able to take to protect your computer equipment from dust depend on a large number of individual circumstances. Regardless of your situation, I recommend you take a three-front defensive position and optimize for each of the following areas:

• Computer room environment
• Protective computer dust barriers
• Computer maintenance

Let’s look at each of these areas individually.

Computer Room Environment
Control the environmental conditions surrounding your computers. The ideal solution would be to keep your computers and monitors in a clean, climate controlled computer room. In other words, take them out of the danger area. Of course, this is unrealistic or undesirable to many shop owners, who want, or need the computers to operate in the immediate work area.

So what then? Do what you can to control the dust and air pollutants in the shop. Use and maintain dust collectors for woodworking machines and a ventilation system for the shop area. And, if you can’t move the computers out of the shop, try to move them across the room, away from welding, grinding or direct contact with billowing sander dust.

Protective Computer Dust Barriers
These include computer dust covers, dust filters, computer dust bags, and computer enclosures. Each has its advantages and limitations as described below. Determine which option is the best solution for you.

Standard computer covers are made by a number of manufacturers. Usually plastic or vinyl, they are cheap, but effective in keeping dust off your computers and monitors. However, they may only be used while your computer equipment is shut down. And, you must remember to put them on. Every day. In other words, they are almost useless in a busy shop.

Computer filters, on the other hand may be used while the computer is running. Also very cheap, these small pieces of loose mesh material are placed over fan air intakes in the computer case to remove dust from incoming air. Some have experimented with using panty hose, Brillo® Pads and other household items with some success. The main drawback with computer filters is their small surface area. They clog up quickly in dusty areas and must be cleaned, or changed frequently to allow the unimpeded flow of cool air into the computer case. Another drawback is that they leave other openings in the computer case unprotected, allowing fine dust to infiltrate the CD ROM drives, floppy drives and other small openings.

Relatively new on the scene, computer dust bags are a combination computer cover and computer filter. Designed for the harsh, dusty and smoky conditions inherent to wood shops and machine shops, these innovative covers entirely encase the computer processor or monitor at all times, allowing the entire surface of the bag to act as a huge dust filter to remove dust from incoming air. Monitor dust bags have a see-through, anti-static front to allow a clear screen view, and are very effective in keeping dust, wood chips and other debris out of the cooling vents. At around $20 or less, the recommended life-span of the computer dust bag is 3-12 months, depending on the level of dust in the shop. A possible drawback to using the computer dust bag is reduced access to CD and floppy drives. However, it is possible to use these drives if you cut a hole in the dust bag and cover it with a door flap, which is included with the bag. You may also have to cut an access slot to use your USB ports.

Finally, computer enclosures are typically metal or wood, box-like cabinets which your computer processor and monitor are placed in to protect them from the surrounding environment. A variety of fan and filter combinations introduce fresh air into the enclosure. Computer enclosures have the added advantage of protecting your equipment from blunt force trauma, such as a falling 2×4, chemical splashes and other things harmful to your computer. Filters must be changed regularly. Disadvantages include high price, greater amount of space required, and filter maintenance.

Computer Maintenance
Finally, the third part of a sound computer dust protection strategy is computer maintenance. Yes, that means cleaning. Does that scare you? It’s easier than you think. You don’t have to buy all kinds of expensive tools and cleaning agents, and no heavy scrubbing or complicated disassembly is needed. The most important thing is to maintain a regular computer cleaning schedule. It may be as simple as opening the computer case once every three months to blow out the dust. Educate yourself on the computer cleaning basics and decide the right course of action for yourself.

Just as numerous insects and animals perish when attacked by the army ant, a great number of computers are killed by dust every day. Don’t let it happen to you. Follow the common sense ideas shown here and stop computer-killing dust in its tracks!

Hurricanes cause billions of dollars in damage each year, including damage to computers. Unfortunately, computers can be much harder to replace if lost than other electronics because of the data contained on their hard drives and time spent tweaking and overclocking them. Being a Katrina evacuee and survivor myself, I know how important a computer can be after a natural disaster. With hurricane season looming in the days ahead, I decided to write a guide to help people protect their computers and data during a natural disaster.

Part I: Backing Up Data And Things to Have

Hurricane season or not, you should always be backing up your data. Whether you plan on riding out the storm (a bad idea) or evacuating to another location, you should have a backup of your computer data either on an external hard drive or optical media such as CD-Rs or a DVD. Be sure to keep your data in a very safe place, such as a water proof safe. Never leave your backup by your computer.

Next, you should have the following things to make life after the storm easier:

Phone numbers for insurance, computer or computer parts companies, and phone numbers for all local ISPs (including dial-up and satellite). Having your insurance phone number and phone numbers for your computer company will help get your computer replaced faster if it is damaged. I can’t stress enough how important it is for you to have phone numbers and even access disks for all of your local ISPs! After Katrina, the Internet was the only way many people could contact the outside world. As fate would have it, my broadband was down for 3 weeks and none of the other broadband ISPs would except new orders due to the storm, leaving me with my old friend Dial Up, whom I thought I had buried 8 years ago. Your best bet is to use a satellite ISP as they have no equipment that can be destroyed by a hurricane and cause an outage.

Back ups of all your file, have all application and game discs, CD keys, drivers, and operating system discs on hand.

Photos of your computer as well as proof of what parts are inside.

In the event your quad SLI rig is destroyed, you don’t want your insurance company to replace it with something of a significantly lesser value, do you? It’s very easy for people to claim “I had this, this, and this and it all cost me $3000 last month.” after their 3 year old Athlon XP rig is destroyed. As a result, your insurance company may be hesitant to replace your expensive computer parts unless you can prove you own them. Also know to what extent your insurance (including flood insurance) will replace damaged property. While some policies will cover the replacement cost of damaged property, some may only cover part of the damage cost. Also know what your deductible is.

Social networking sites such as myspace were great after Katrina. Friends could find out where other friends had evacuated to simply by reading each others’ myspaces.

A generator can power many things, including home computers! Check with your local generator supplier about any local laws about generators, how to safely and properly set one up, and how well they will work with computers. Because generators provide unstable power, a battery backup UPS and a surge protector are a must. Do not count on gas to power your generator being available in the aftermath of the storm. It’s best to have a good supply of gas as well as a few empty gas containers on hand.

Part II: Evacuating with Your PC

Like any family members or pets you may have, your PC isn’t something to leave behind if you can avoid it. While your first priority should be getting out alive, you should consider bringing your PC with you if you can room in your car. You can’t count on your destination to have good computers, high speed Internet, or any entertaining activities for that matter. Being in another place during a hurricane is stressful. Between watching your home town being walloped on CNN and The Weather Channel, the people around you as well as yourself will be tense and worried. Having a nice computer to browse the web with and play Battlefield 2 is a sure entertainer. In fact, the Internet was the only place where I could get information about my very neighborhood after the storm! Local newspaper message boards were packed with evacuees from all over my area and had plenty of information about damage to share.

Even if you can’t bring your PC, at the very least bring your hard drive with you! If your home is looted in the aftermath of the storm, the last thing you want is your personal data in someone else’s hands. Be sure your hard drive is in an anti-static bag to avoid needless damage to it.

If taking a long road trip, you should probably place some sort of padding or foaming (even a blanket will work) around your computer or hard drive to protect it from the vibrations of the car. Don’t bring your monitor unless you have an LCD and there’s room for it.

Part III: Leaving Your PC at Home

If you don’t have room for your PC in your car, don’t plan on staying with it during the storm. There are several safeguards you can take to prevent unnecessary damage to your computer:

Cover any open parts of your computer case (such as fans and vents) with tape. Don’t use duct tape unless you want to risk taking paint off your case or a sticky mess.

Cover your computer with as many trash bags as you need. At least 2 trash bags per computer are recommended.

Consider how high your home is above sea level, the risk of flooding, and other factors. If you know your home could flood, you should put your computer on the second floor. But if you know your roof is weak and could easily blow off, don’t put it on the second floor! Find an enclosed space with no windows (such as a closet) as close to the center of your home as possible. If your computer case has a side window, make sure it’s facing towards the ground or against a wall. If you can, place other objects around your computer to offer it additonal protection from blowing rain and flying debris.

Part IV: When the Worst Happens

In the event your PC becomes damaged during the storm, don’t fret. If the damage is from a fallen tree or a piece of flying debri, there is nothing you can do. If your computer becomes flooded, however, there are steps you can take to recover it. Below is a basic guide on how to recover a flooded computer.

Do not turn on the computer! Make sure it is unplugged! While you may be anxious to see if your computer can run, don’t do it if you know it’s been exposed to water. You’ll just end up causing more damage if you do. Remember to keep your computer unplugged.

Remove components that work. If you can see a water line in your computer, take out all the components above it and put them in a safe place.

Let your computer dry. Let your computer dry for a week or so. One drop of water in a running computer could mean disaster.

Remove the CMOS battery and other parts.

Use a solution of 90% alcohol or more to wash the various components of your computer, including connectors. If necessary, use a paint brush to remove stubbon crud.

Let your computer dry completely.

If the above doesn’t work or you have data you can’t risk losing on your hard drive, consider professional computer recovery. Do not plan on salvaging the power supply, CMOS battery, the hard drive, optical drives, or any fans if they have been flooded. Also remember to take pictures of any damage to your computer before you attempt to fix it for insurance purposes.

Hopefully this guide will help people save their computers from hurricane related damage. A computer is a very useful tool that should be part of any good disaster supply kit. Trust me when I say it’s an important thing to have around. However, remember a computer is only a material possession. Like all material objects, they can be replaced. Human and animal life, however, cannot. Use good judgement when deciding whether or not to take your computer with you and while repairing it if it damaged.

Disclaimer: In no way is the author responsible for any actions you may take to save your computer from a hurricane or fix it after flooding. Any actions you choose regarding hurricanes and computers are taken at your own risk. For the sake of all, please use common sense during any natural disaster.

With the rapid pace of technological developments, nothing has become as ubiquitous as the computer. Everyone’s got one. And they are used for all manner of endeavour, by people of all walks of life. So, do you simply buy the computer that someone’s selling? Or do you do some homework and figure out what detailed specifications are going to make some difference to you?

At Myshopping.com.au you can compare the prices of a wide range of different computers from different vendors and of different specifications. This guide will help you find what you’re looking for.

Mac or Windows (PC)

At the outset, you need to decide what you are going to use the computer for. This will help you make the fundamental decision of whether you should go Mac or PC. Although, with the advent of the dual core processor (an Intel chip now used by Mac) the differences are narrowed a little, there are still some choices that can help you favour one system over another. Historically, Mac computers have a reputation for greater stability that comes from a more robust operating system than Windows based computers. Largely for this reason, Macs have been the computer of choice for the graphic design industry, the music production industry and the video production industry. This has prompted the software manufacturers to make professional software packages for these disciplines that favour the Mac operating system. Although they have packages supporting the Windows operating system, they are often less capable.

Consequently, if you are engaged in these industries and need your computer for this type of work, you should consider Mac. Mac computers appear to attract fewer viruses and software malfunctions than do Windows based PCs. On the down side, there has always appeared to have been limited software support for Mac systems.

Another decision that may guide your choice is the aesthetics of the computer. If you have limited available space, there is nothing quite like the iMacs or the mini Macs for space saving. iMac’s all-in-one desktop units are compact and complete with all the connectivity you need. However, the look of other brands may be more to your taste, with many models available in compact packages and modern colour schemes to suit practically all dÊcor. Now that you’ve made that basic decision, you can start comparing the apples with apples.

The Components of Your Computer

The two factors that determine the price of your computer are size (yes it does matter) and speed. Either or both of these two dimensions are a factor of practically every component that makes up the machine. Naturally the highest price tags go with the combination of biggest and fastest.

CPU

The heart of the computer is the CPU (central processing unit). You need to decide which CPU you want driving your computer. These come from different manufacturers, and the current development of the technology is called Dual Core, which means that there are two processors on the one chip. Dual Core technology delivers more performance with less energy requirements. Intel and AMD are the two leading CPU manufacturers, and they offer different products under different names.

Current processing speeds range from about 1.4 GHz (gigahertz) through to 3.46 GHz. But it is not simply just a matter of speed. There are other considerations. Mac Operating Systems have a different architecture to Windows and will perform many functions faster with a slower speed CPU. A dual core chip at 1.4 GHz will deliver a better performance that a Pentium 4 chip at 1.8 GHz. A 1.4 GH dual core chip running a Mac with OSX Tiger, will perform better than a 2.0 GHz Pentium 4 processor running Windows. You need to decide what you want your computer to do, what your major software requirements are before you decide on the CPU processor.

However, for everyday use, a processor faster than 1.8 GHz will deliver excellent performance. As a rough rule of thumb, choose a Celeron for low cost computing, a Pentium 4 for mid-range budgets, or an AMD Athlon for bigger budgets. You can compare computers based on Pentium, Celeron, Athlon or Dual Core CPUs by searching those specifications on Myshopping.com.au and finding different vendors and brands using different processors.

RAM

This is where bigger definitely means better performance. RAM is the system memory that enables the computer to use its programs and swap data between the hard drive and the program functions. It’s important to match the speed of the RAM of your computer with the speed of the CPU. The more RAM you have available for your programs to work, the faster will your computer run. Most computers today come with at least 256 M (megabytes) of RAM. But memory is a relatively cheap component, and it costs little extra to upgrade to 512 M or greater.

HARD DRIVE

The hard drive of the computer stores your program files and your data. As computers have advanced, so has the need for more capacity to operate programs and store data. People working in media fields tend to work with very large files and require large storage space. Most computers in today’s market come with a minimum of 40G of hard drive space. However, this can be upgraded (usually in 20G chunks) to as much as 200G or more. The effectiveness of your hard drive also can depend on its physical speed (5400-7200 RPM) and the speed at which it can transfer data between the computer’s RAM and the hard drive. Faster means better performance.

REMOVABLE MEDIA

You will want to have a CD-R or (CD-RW) drive installed in your computer, and or possibly a DVD or DVD-R. For reading a CD ROM, all that is required is a CD drive and for watching DVD movies, a DVD ROM drive. However with a CD-R drive, you can record your own data and music CDs, and with a DVD-R drive, you can burn files in a DVD format, allowing you to store movies and data in far greater quantities. The CD-RW (DVD-RW) drives allow you to use re-recordable media. Your decision will depend on what you want to use your media drives for and what you want to store.

Other removable media will possibly include flash card storage, which is usually plugged in via the USB ports on the computer.

MONITORS

The monitor for your computer is integral to its function and aesthetics. If you are working in graphics you may want to stay with a CRT monitor. However most bundle offers these days are supplied with LCD monitors, which have the advantages of smaller space requirements, use lower energy and offer wider screen images. However they generally are more expensive (although prices are dropping everyday), can frequently be not as bright, have limited viewing angles and sometimes require a digital interface connector.

For graphics intensive work, LCD screens do not have the same capacity to render colours in gradients as CRT monitors. Once again, size matters. Bigger screens cost more than smaller ones.

VIDEO AND SOUND

For a detailed explanation of video cards, please see the article on Myshopping.com.au dedicated to Video Cards.

The interface between the CPU and the Monitor is provided by the video card. One of the basic decisions you need to make is whether you require a 3D or 2D card. Video cards come in two different types: those that use an AGP (accelerated graphics port) on the computer motherboard and those that use the PCI bus. Data transfer rate is critical to video performance. Faster video cards use an AGP, and this proves a faster data transfer than PCI cards. Most video cards also have their own video memory installed on the card, a feature that increases a computer’s memory performance. Today, these memories are often 128M or 256M, and can be more in the higher-end cards dedicated to sophisticated video work or gaming. Video cards performance is also affected by what is known as clock speed or clock rate, cards with a faster speed offer faster performance.

Cheaper computers, and laptops and notebooks, have an integrated graphics chip included in the motherboard instead of a discrete video card. This type of configuration is not as powerful or as fully functional as having a separate video card, which can allow more comprehensive gaming, the use of multiple monitors and faster and better rendering of images.

For a computer to reproduce the sounds recorded in games, movies and music products it requires a sound card. Quality of sound can be affected by the sound card your computer has installed. It’s important that you know how you want to use the sound reproduction processes of your computer. If you are a musician and want to record audio, then you will want to be sure that you have excellent connectivity, good midi access and at least 16-bit (CD quality) audio reproduction. Sound cards give you the possibilities of full cinema surround sound, and the many subtle effects employed by high-end games.

Nearly every computer comes with a set of stereo speakers. However it pays to have a good listen to what you’re buying. Make sure you listen to program that you are familiar with (take your own CD along) and compare the sound in a quiet environment. Many speaker systems for computers have poor frequency response and are underpowered. For desktop use that does not involve a quality listening environment this may be satisfactory. But if you want to listen to music and watch movies for the full effect, then you need to consider buying a good quality set of speakers. Use the search facility of Myshopping.com.au to compare specifications and prices of different speaker systems.

KEYBOARD AND MOUSE

The choice of keyboard and mouse are personal choices. Sometimes it depends on what you do on your computer, whether you have formal typing skills or whether you’re a two-finger hack. Serious writers may prefer an ergonomic keyboard. Keyboards frequently have different clicks and responses to others. You may prefer an infrared cordless keyboard and mouse. You may prefer an optical mouse on which you don’t have to clean the rollers. Optical mice have no rollerball, and can be used on most flat surfaces, but they are more expensive.

CONNECTIVITY

Today, connectivity is everything. Your computer can have wireless connections to all of your peripherals: printer, scanner, and other computers. Having an onboard modem will only be really important if you are using a dial up internet connection. Broadband modems tend to be peripherals and you can connect via USB, wireless or firewire. It does pay to consider how you will connect to the internet and other peripherals. It’s not always convenient to get behind your computer to plug something in or unplug it. Some sound cards have a front face panel with all the connections you need. The USB ports on Macs are conveniently located. Many PC manufacturers haven’t caught on to the fact that it’s important for some people to easily access the connections to their computers.

To compare the different bundle offers from different brands, and to compare the different components by their specifications, search the Myshopping.com.au database for exactly the specifications you are seeking. You can compare prices and vendors, and order what you need online with a few clicks.

In 1983, Fred Cohen coined the term “computer virus”, postulating a virus was “a program that can ‘infect’ other programs by modifying them to include a possibly evolved copy of itself.” The term virus is actually an acronym for Vital Information Resources Under Seize. Mr. Cohen expanded his definition a year later in his 1984 paper, “A Computer Virus”, noting that “a virus can spread throughout a computer system or network using the authorizations of every user using it to infect their programs. Every program that gets infected may also act as a virus and thus the infection grows.” Computer viruses, as we know them now, originated in 1986 with the creation of Brain – the first virus for personal computers. Two brothers wrote it (Basid and Farooq Alvi who ran a small software house in Lahore, Pakistan) and started the race between viruses and anti-virus programs which still goes on today.
Using the above explanation, it can be said that viruses infect program files. However, viruses can also infect certain types of data files, specifically those types of data files that support executable content, for example, files created in Microsoft Office programs that rely on macros.
Compounding the definition difficulty, viruses also exist that demonstrate a similar ability to infect data files that don’t typically support executable content – for example, Adobe PDF files, widely used for document sharing, and .JPG image files. However, in both cases, the respective virus has a dependency on an outside executable and thus neither virus can be considered more than a simple ‘proof of concept’. In other cases, the data files themselves may not be infectable, but can allow for the introduction of viral code. Specifically, vulnerabilities in certain products can allow data files to be manipulated in such a way that it will cause the host program to become unstable, after which malicious code can be introduced to the system. These examples are given simply to note that viruses no longer relegate themselves to simply infecting program files, as was the case when Mr. Cohen first defined the term. Thus, to simplify and modernize, it can be safely stated that a virus infects other files, whether program or data.
Computer viruses are called viruses because they share some of the traits of biological viruses. A computer virus passes from computer to computer like a biological virus passes from person to person.
There are similarities at a deeper level, as well. A biological virus is not a living thing. A virus is a fragment of DNA inside a protective jacket. Unlike a cell, a virus has no way to do anything or to reproduce by itself — it is not alive. Instead, a biological virus must inject its DNA into a cell. The viral DNA then uses the cell’s existing machinery to reproduce itself. In some cases, the cell fills with new viral particles until it bursts, releasing the virus. In other cases, the new virus particles bud off the cell one at a time, and the cell remains alive.
A computer virus shares some of these traits. A computer virus must piggyback on top of some other program or document in order to get executed. Once it is running, it is then able to infect other programs or documents. Obviously, the analogy between computer and biological viruses stretches things a bit, but there are enough similarities that the name sticks.
A computer virus is a program that replicates. To do so, it needs to attach itself to other program files (for example, .exe, .com, .dll) and execute whenever the host program executes. Beyond simple replication, a virus almost always seeks to fulfill another purpose: to cause damage.
Called the damage routine, or payload, the destructive portion of a virus can range from overwriting critical information kept on the hard disk’s partition table to scrambling the numbers in the spreadsheets to just taunting the user with sounds, pictures, or obnoxious effects.
It’s worth bearing in mind, however, that even without a ”damage routine”, if viruses are allowed to run unabated then it will continue to propagate–consuming system memory, disk space, slowing network traffic and generally degrading performance. Besides, virus code is often buggy and can also be the source of mysterious system problems that take weeks to understand. So, whether a virus is harmful or not, its presence on the system can lead to instability and should not be tolerated.
Some viruses, in conjunction with “logic bombs,” do not make their presence known for months. Instead of causing damage right away, these viruses do nothing but replicate–until the preordained trigger day or event when they unleash their damage routines on the host system or across a network.
Impact of Viruses on Computer Systems
Virus can be reprogrammed to do many kinds of harm including the following.
1.Copy themselves to other programs or areas of a disk.
2.Replicate as rapidly and frequently as possible, filling up the infected system’s disk and memory rendering the systems useless.
3.Display information on the screen.
4.Modify, corrupt or destroy selected files.
5.Erase the contents of entire disks.
6.Lie dormant for a specified time or until a given condition is met, and then become active.
7.Open a back door to the infected system that allows someone else to access and even control of the system through a network or internet connection.
8.Some viruses can crash the system by causing some programs (typically Windows) to behave oddly.
How viruses spread from one system to another?
The most likely virus entry points are email, Internet and network connections, floppy disk drives, and modems or other serial or parallel port connections. In today’s increasingly interconnected workplace (Internet, intranet, shared drives, removable drives, and email), virus outbreaks now can spread faster and wider than ever before.
The following are some common ways for a virus to enter the users’ computer system:
•Email attachments
•Malicious scripts in web pages or HTML email
•FTP traffic from the Internet (file downloads)
•Shared network files & network traffic in general
•Demonstration software
•Pirated software
•Shrink-wrapped, production programs (rare)
•Computer labs
•Electronic bulletin boards (BBS)
•Diskette swapping (using other people’s diskettes for carrying data and programs back and forth)
High risk files
The most dangerous files types are:
.EXE, .COM, .XLS, .DOC, .MDB
Because they don’t need any special conversion to infect a computer — all they’ve got to do is run and consequently the virus spreads. It has been estimated that 99% of all viruses are written for these file formats.
A list of possible virus carriers includes:
EXE – (Executable file)
SYS – (Executable file)
COM – (Executable file)
DOC – (Microsoft Word)
XLS – (Microsoft Excel)
MDB – (Microsoft Access)
ZIP – (Compressed file, common in the USA)
ARJ – (Compressed file, common in the USA)
DRV – (Device driver)
BIN – (Common boot sector image file)
SCR – (Microsoft screen saver)
Common Symptoms Of Virus Infection
Computer does not boot.
Computer hard drive space is reduced.
Applications will not load.
An application takes longer to load than normal time period.
Hard dive activity increases especially when nothing is being done on the computer.
An anti virus software message appears.
The number of hard drive bad sectors steadily increases.
Unusual graphics or messages appear on the screen
Files are missing (deleted)
A message appears that hard drive cannot be detected or recognized.
Strange sounds come from the computer.
Some viruses take control of the keyboard and occasionally substitute a neighboring key for the one actually pressed. Another virus “swallows” key presses so that nothing appears on the screen.
Also interesting are system time effects. Clocks going backwards are especially frightening for workers who cannot wait to go home. More seriously though, this type of virus can cause chaos for programs which depend on the system time or date.
Some viruses can cost the user dearly by dialing out on his modem. We do not know of one which dials premium telephone numbers but no doubt we shall see one soon. One particularly malicious virus dials 911 (the emergency number in the USA) and takes up the valuable time of the emergency services.
Categories of viruses
Depending on the source of information different types of viruses may be categorized in the following ways:
PDA VIRUSES
The increasing power of PDAs has spawned a new breed of viruses. Maliciously creative programmers have leveraged the PDA’s ability to communicate with other devices and run programs, to cause digital mayhem.
The blissfully safe world where users of these devices could synchronize and download with impunity came to an end in August 2000 with the discovery of the virus Palm Liberty. Since then, many more viruses have been discovered.
Though not yet as harmful as their PC-based cousins, these viruses still pose a threat to unsuspecting users. Their effects vary from the harmless flashing of an unwanted message or an increase in power consumption, to the deletion of all installed programs. But the threat is growing, and the destructiveness of these viruses is expected to parallel the development of the devices they attack.
MULTIPARTITE VIRUSES
A virus that combines two or more different infection methods is called a multipartite virus. This type of virus can infect both files and boot sector of a disk. Multi-partite viruses share some of the characteristics of boot sector viruses and file viruses: They can infect .com files, .exe files, and the boot sector of the computer’s hard drive. On a computer booted up with an infected diskette, the typical multi-partite virus will first make itself resident in memory then infect the boot sector of the hard drive. From there, the virus may infect a PC’s entire environment. Not many forms of this virus class actually exist. However, they do account for a disproportionately large percentage of all infections. Tequila and Anticad are the examples of multipartite viruses.
BOMBS
The two most prevalent types of bombs are time bombs and logic bombs. A time bomb hides on the victim’s disk and waits until a specific date before running. A logic bomb may be activated by a date, a change to a file, or a particular action taken by a user or a program. Bombs are treated as viruses because they can cause damage or disruption to a system.
BOOT SECTOR VIRUSES
Until the mid-1990s, boot sector viruses were the most prevalent virus type, spreading primarily in the 16-bit DOS world via floppy disk. Boot sector viruses infect the boot sector on a floppy disk and spread to a user’s hard disk, and can also infect the master boot record (MBR) on a user’s hard drive. Once the MBR or boot sector on the hard drive is infected, the virus attempts to infect the boot sector of every floppy disk that is inserted into the computer and accessed. Examples of boot sector viruses are Michelangelo, Satria and Keydrop.
Boot sector viruses work like this: Let us assume that the user received a diskette with an infected boot sector. The user copied data from it but forgot to remove it from drive A:. When he started the computer next time the boot process will execute the infected boot sector program from the diskette. The virus will load first and infect the hard disk. Note that this can be prevented by changing the boot sequence in CMOS (Let C: drive boot before A:). By hiding on the first sector of a disk, the virus is loaded into memory before the system files are loaded. This allows it to gain complete control of DOS interrupts and in the process replaces the original contents of the MBR or DOS boot sector with their own contents and move the original boot sector data to another area on the disk. Because the virus has infected a system area of the hard disk it will be loaded into memory each time the computer is started. It will first take control of the lowest level disk system services before executing the original boot sector code which it has stored in another part of the hard disk. The computer seems to behave exactly as it should. Nobody will notice the extra few fractions of a second added to the boot sequence.
During normal operation the virus will happily stay in memory. Thanks to the fact that it has control of the disk services it can easily monitor requests for disk access – including diskettes. As soon as it gets a request for access to a diskette it will determine that there is a diskette in the floppy drive. It will then examine its boot sector to see if it has already been infected. If it finds the diskette clean it will replace the boot sector with its own code. From this moment the diskette will be a “carrier” and become a medium for infections on other PC’s.
The virus will also monitor special disk requests for access to the boot sector. The boot sector contains its own code, and a request to read it could be from an anti-virus program checking for virus presence. The virus will not allow the boot sector to be read and will redirect all requests to the place on the hard disk where it has backed up the original contents. In this way nothing unusual is detected. Such methods are called stealth techniques and their main goal is to mask the presence of the virus. Not all boot viruses use stealth but those which do are common.
Boot viruses also infect the non-file (system) areas of hard and floppy disks. These areas offer an efficient way for a virus to spread from one computer to another. Boot viruses have achieved a higher degree of success than program viruses in infecting their targets and spreading.
Boot virus can infect DOS, Windows 3.x, Windows 95/98, Windows NT, and even Novell Netware systems. This is because they exploit inherent features of the computer (rather than the operating system) to spread and activate.
Cleaning up a boot sector virus can be performed by booting the machine from an uninfected floppy system disk rather than from the hard drive, or by finding the original boot sector and replacing it in the correct location on the disk.
CLUSTER VIRUSES
This type of virus makes changes to a disks file system. If any program is run from the infected disk, the program causes the virus to run as well. This technique creates the illusion that the virus has infected every program on the disk.
E-MAIL VIRUSES
These types of viruses can be transmitted via e-mail messages sent across private networks or the internet. Some e-mail viruses are transmitted as an infected attachment- a document file or program that is attached to the message. This type of virus is run when the victim opens the file that is attached to the message. Other types of email viruses reside within the body of the message itself. To store a virus, the message must be encoded in html format. Once launched many e-mail viruses attempt to spread by sending messages to everyone in the victim’s address book; each of those contains a copy of the virus.
The latest thing in the world of computer viruses is the e-mail virus called Melissa virus which surfaced in March 1999. Melissa spread in Microsoft Word documents sent via e-mail, and it worked like this:
Someone created the virus as a Word document uploaded to an Internet newsgroup. Anyone who downloaded the document and opened it would trigger the virus. The virus would then send the document (and therefore itself) in an e-mail message to the first 50 people in the person’s address book. The e-mail message contained a friendly note that included the person’s name, so the recipient would open the document thinking it was harmless. The virus would then create 50 new messages from the recipient’s machine. As a result, the Melissa virus was the fastest-spreading virus ever seen and it forced a number of large companies to shut down their e-mail systems at that time.
The ILOVEYOU virus, which appeared on May 4, 2000, was even simpler. It contained a piece of code as an attachment. People who double clicked on the attachment allowed the code to execute. The code sent copies of itself to everyone in the victim’s address book and then started corrupting files on the victim’s machine. This is as simple as a virus can get. It is really more of a Trojan horse distributed by e-mail than it is a virus.
The Melissa virus took advantage of the programming language built into Microsoft Word called VBA, or Visual Basic for Applications. It is a complete programming language and it can be programmed to do things like modify files and send e-mail messages. It also has a useful but dangerous auto-execute feature. A programmer can insert a program into a document that runs instantly whenever the document is opened. This is how the Melissa virus was programmed. Anyone who opened a document infected with Melissa would immediately activate the virus. It would send the 50 e-mails, and then infect a central file called NORMAL.DOT so that any file saved later would also contain the virus! It created a huge mess.
FILE INFECTING VIRUSES
File infectors operate in memory and usually infect executable files with the following extensions: *.COM, *.EXE, *.DRV, *.DLL, *.BIN, *.OVL, *.SYS. They activate every time the infected file is executed by copying themselves into other executable files and can remain in memory long after the virus has activated.
Thousands of different file infecting viruses exist, but similar to boot sector viruses, the vast majority operates in a DOS 16-bit environment. Some, however, have successfully infected the Microsoft Windows, IBM OS/2, and Apple Computer Macintosh environments.
File viruses can be separated further into sub-categories by the way they manipulate their targets:
TSR FILE VIRUSES
A less common type of virus is the terminate-and-stay-resident file virus. As the name suggests these infect files usually these are .com and .exe files. there are however some device driver viruses, some viruses that infect overlay files, and although over 99% of executable programs have the extension .com and .exe, some do not .For a TSR virus to spread some one has to run an infected program. The virus goes memory resident typically looking at each program run thereafter and infects it. Examples of TSR file viruses are Dark Avenger and Green Caterpillar.
OVERWRITING VIRUSES
These viruses infect by overwriting part of their target with their own code but, by doing so, they damage the file. The file will never serve another purpose other than spreading the virus further. Because of this they are usually detected quickly and do not spread easily.
PARASITIC VIRUSES
These viruses attach themselves to executables without substantially changing the contents of the host program. They attach by adding their code to the beginning, end, or even middle of the file and divert program flow so that the virus is executed first. When the virus has finished its job, control is passed on to the host. Execution of the host is a little delayed but this is usually not noticeable.
MACRO VIRUSES
Many older applications had simple macro systems that allowed the user to record a sequence of operations within the application and associate them with a specific keystroke. Later, the user could perform the same sequence of operations by merely hitting the specified key.
Newer applications provide much more complex macro systems. User can write entire macro-programs that run within the word processor or spreadsheet environment and are attached directly onto word processing and spreadsheet files. Unfortunately, this ability also makes it possible to create macro viruses.
Macro viruses currently account for about 80 percent of all viruses, according to the International Computer Security Association (ICSA), and are the fastest growing viruses in computer history. Unlike other virus types, macro viruses aren’t specific to an operating system and spread with ease via email attachments, floppy disks, Web downloads, file transfers, and cooperative applications.
Macro viruses are, however, application-specific. A macro virus is designed to infect a specific type of document file, such as Microsoft word or excel files. They infect macro utilities that accompany such applications as Microsoft Word and Excel, which means a Word macro virus cannot infect an Excel document and vice versa. A macro virus is embedded in a document file and can travel between data files in the application and can eventually infect hundreds of files if undeterred and in the process do various levels of damage to data from corrupting documents to deleting data.
Macro viruses are written in “every man’s programming language” — Visual Basic — and are relatively easy to create. They can infect at different points during a file’s use, for example, when it is opened, saved, closed, or deleted
A typical chronology for macro virus infection begins when an infected document or spreadsheet is loaded. The application also loads any accompanying macros that are attached to the file. If one or more of the macros meet certain criteria, the application will also immediately execute these macros. Macro viruses rely upon this auto-execution capability to gain control of the application’s macro system.
Once the macro virus has been loaded and executed, it waits for the user to edit a new document, and then kicks into action again. It attaches its virus macro programs onto the new document, and then allows the application to save the document normally. In this fashion, the virus spreads to another file and does so in a completely discrete fashion. Users have no idea of the infection. If this new file is later opened on another computer, the virus will once again load, be launched by the application, and find other unsuspecting files to infect.
Finally, as far as a macro virus is concerned, the application serves as the operating system. A single macro virus can spread to any of the platforms on which the application is installed and running. For example, a single macro virus that uses Microsoft Word could conceivably spread to Windows 3.x, Windows 95/98, Window NT, and the Macintosh.
Macro viruses for Word
In the summer of 1995, Microsoft Word 6 was the first product affected with macro virus. The first one (WM/Concept.A) was really only a proof of concept – one of the installed macros (called Payload) contained only this remark:
“That’s enough to prove my point”
Most macro viruses for Word use a feature called ‘automacros’. The basic principle is that some macros with special names are automatically executed when Word starts, opens a file, or closes a file. The macro virus then inserts macros into NORMAL.DOT – a standard template which is loaded every time Word starts.
In Word there are some ways to disable automacros but this isn’t the ultimate solution. Some macro viruses use other methods to take control over the Word environment.
Another method of self-protection may be to set NORMAL.DOT to read only. But this can also be bypassed and, in addition, it prevents the user from customizing the template.
Macro viruses for Excel
Excel has the same opportunities for virus authors as Word. It has automacros and a directory called XLSTART from which templates are automatically loaded.
But Excel does not have just normal VBA macros like Word. In Excel there are so called ‘formulas’ – macros stored in spreadsheet cells. The first macro virus using this technology was XF/Paix.
Macro viruses for other MS Office products:
Writing a macro virus for other Office products is not difficult. There have been already some viruses for Access, and it is expected that there will be macro viruses for Power Point in the near future.
But those macro viruses are not as dangerous as the macro viruses for Word or Excel. Not because of some limitation of these other Office products, but because data files from these products are not so frequently shared.
There is one danger which can be seen in today’s Power Point even without native macro viruses written for this product. Programmers can include in their presentation any number of objects from Excel or Word. And these objects can be infected with macro viruses – if they edit the presentation and open the infected object with its parent application, then the virus can spread further.
But the current situation may change dramatically over the next few years. Microsoft has licensed VBA technology to many firms, so one can expect to see more macro viruses for other products, too.
POLYMORPHIC VIRUSES
This type of virus can change itself each time it is copied, making it difficult to isolate. Most simple viruses attach identical copies of themselves to the files they infect. An anti-virus program can detect the virus’s code (or signature) because it is always the same and quickly ferret out the virus. To avoid such easy detection, polymorphic viruses operate somewhat differently. Unlike the simple virus, when a polymorphic virus infects a program, it scrambles its virus code in the program body. This scrambling means that no two infections look the same, making detection more difficult. These viruses create a new decryption routine each time they infect, so every infected file will have a different sequence of virus code.
STEALTH VIRUSES
Stealth viruses actively seek to conceal themselves from attempts to detect or remove them. They also can conceal changes they make to other files, hiding the damage from the user and the operating system.
Stealth viruses, or Interrupt Interceptors, as they are sometimes called, take control of key DOS-level instructions by intercepting the interrupt table, which is located at the beginning of memory. This gives the virus the ability to do two important things: 1) gain control of the system by re-directing the interrupt calls, and 2) hide itself to prevent detection. They use techniques such as intercepting disk reads to provide an uninfected copy of the original item in place of the infected copy (read-stealthing viruses), altering disk directory or folder data for infected program files (size-stealthing), or both. For example, the Whale virus is a size-stealthing virus. It infects .EXE program files and alters the folder entries of infected files when other programs attempt to read them. The Whale virus adds 9216 bytes to an infected file. Because changes in file size are an indication that a virus might be present, the virus then subtracts the same number of bytes (9216) from the file size given in the directory/folder entry to trick the user into believing that the file’s size has not changed.
An antivirus program which is not equipped with anti-stealth technology will be deceived.
COMPANION VIRUSES
A companion virus is the exception to the rule that a virus must attach itself to a file. The companion virus instead creates a new file and relies on a behavior of DOS to execute it instead of the program file that is normally executed. These viruses target EXE programs. They create another file of the same name but with a COM extension containing the virus code. These viruses take advantage of a property of MS-DOS which allows files to share the same first name in the same directory (e.g. ABC.EXE and ABC.COM) but executes COM files in preference to EXE files.
For example, the companion virus might create a file named CHKDSK.COM and place it in the same directory as CHKDSK.EXE. Whenever DOS must choose between executing two files of the same name where one has an .EXE extension and the other a .COM extension, it executes the .COM file. This is not an effective way of spreading but has one big advantage – it does not amend files in any way and so can escape integrity tests or resident protection. Another method which can be used by companion viruses is based on defined path. A virus simply puts an infected file into the path listed before the directory within the original program.
PROGRAM VIRUSES
Like normal programs, program viruses must be written for a specific operating system. The vast majority of viruses are written for DOS but some have been written for Windows 3.x, Windows 95/98, and even UNIX. All versions of Windows are compatible with DOS and can host DOS viruses with varying degrees of success. Program viruses infect program files, which commonly have extensions such as .COM, .EXE, .SYS, .DLL, .OVL, or .SCR. Program files are attractive targets for virus writers because they are widely used and have relatively simple formats to which viruses can attach.
Malicious Programs and Scripts
Viruses that infect agent programs (such as those that download software from the Internet; for example, JAVA and ActiveX).
WORM
A worm is a computer program that has the ability to copy itself from machine to machine. Worms normally move around and infect other machines through computer networks. An entire LAN or corporate e-mail system can become totally clogged with copies of a worm, rendering it useless. Worms are commonly spread over the internet via e-mail message attachments and through internet relay chat channels.
For example, the Code Red worm replicated itself over 250,000 times in approximately nine hours on July 19, 2001.
A worm usually exploits some sort of security hole in a piece of software or the operating system. For example, the Slammer worm (which caused mayhem in January 2003) exploited a hole in Microsoft’s SQL server.
Worms use up computer time and network bandwidth when they are replicating, and they often have some sort of evil intent. A worm called Code Red made huge headlines in 2001. Experts predicted that this worm could clog the Internet so effectively that things would completely grind to a halt.
The Code Red worm slowed down Internet traffic when it began to replicate itself, but not nearly as badly as predicted. Each copy of the worm scanned the Internet for Windows NT or Windows 2000 servers that do not have the Microsoft security patch installed. Each time it found an unsecured server, the worm copied itself to that server. The new copy then scanned for other servers to infect. Depending on the number of unsecured servers, a worm could conceivably create hundreds of thousands of copies.
The Code Red worm was designed to do three things:
•Replicate itself for the first 20 days of each month
•Replace Web pages on infected servers with a page that declares “Hacked by Chinese”
•Launch a concerted attack on the White House Web server in an attempt to overwhelm it
The most common version of Code Red is a variation, typically referred to as a mutated strain, of the original Ida Code Red that replicated itself on July 19, 2001.
TROJAN HORSES
Trojans, another form of malware, are generally agreed upon as doing something other than the user expected, with that “something” defined as malicious. Most often, Trojans are associated with remote access programs that perform illicit operations such as password-stealing or which allow compromised machines to be used for targeted denial of service attacks. One of the more basic forms of a denial of service (DoS) attack involves flooding a target system with so much data, traffic, or commands that it can no longer perform its core functions. When multiple machines are gathered together to launch such an attack, it is known as a distributed denial of service attack, or DDoS.
Because Trojan horses do not make duplicates of themselves on the victims disk (or copy themselves to other disks), they are not technically viruses. But because they can do harm, many experts consider them to be a type of virus. Trojan horses are often used as by hackers to create a back door to an infected system. Trojans, such as BackOrrifice are very dangerous. If anyone runs this program and his computer is connected to the internet, then the hacker can take control of that computer – transfer files to or from the computer, capture screen contents, run any program or kill any running process, etc.
Once a Trojan is installed onto the system this program has the same privileges as the user of the computer and can exploit the system to do something the user did not intend such as:
Delete files
Transmit to the intruder any files that the user can read
Change any files that the user can modify
Install other programs with the user’s privileges
Execute privilege-elevation attacks—the Trojan can attempt to exploit a weakness to raise the level of access beyond the user running the Trojan. If successful, the Trojan can operate with increased privileges.
Install viruses
Install other Trojans
The Following Tips Will Help The User To Minimize Virus Risk:
If the users are truly worried about traditional (as opposed to e-mail) viruses, they should be running a more secure operating system like UNIX. One should never hear about viruses on these operating systems because the security features keep viruses (and unwanted human visitors) away from the hard disk.
If the users are using an unsecured operating system, then buying virus protection software is a nice safeguard. Some popular anti virus programs include:
•McAfee Virus Scan
•Norton Anti Virus
•Virex
•PC—cillin
•Avast!
•AVG Anti Virus System
Automatic protection of anti-virus software should be turned on at all times.
The users should perform a manual scan (or schedule a scan to occur automatically) of their hard disks weekly. These scans supplement automatic protection and confirm that the computer is virus-free.
Scan all floppy disks before first use.
Disable floppy disk booting — most computers now allow the user to do this, and that will eliminate the risk of a boot sector virus coming in from a floppy disk accidentally left in the drive.
The users should Enable Automatic Update option of their anti-virus software in order to update their virus definition files.
Creation and maintenance of a rescue disk should be done by the user in order to facilitate recovery from certain boot viruses.
Periodic backups of the hard disk should be done.
Users’ should buy legal copies of all software they use and make write-protected backups.
 Email messages and email attachments from unknown people should not be opened. Attachments that come in as Word files (.DOC), spreadsheets (.XLS), images (.GIF and .JPG), etc., are data files and they can do no damage (noting the macro virus problem in Word and Excel documents mentioned above). A file with an extension like EXE, COM or VBS is an executable, and an executable can do any sort of damage it wants. Further it should be verified that the “author” of the email has sent the attachments. Newer viruses can send email messages that appear to be from a person user know.
The potential users should make sure that Macro Virus Protection is enabled in all Microsoft applications, and they should never run macros in a document unless they know specifically the functionality of the macros.
Appropriate Passwords should be assigned to the shared network drives.
Things that are not viruses!
Joke programs
Joke programs are not viruses and do not inflict any damage. Their purpose is to frighten their victims into thinking that a virus has infected and damaged their system. For example, a joke program may display a message warning the user not to touch any keys or else the computer’s hard disk will be formatted.
Droppers
A dropper is a program that is not a virus, nor is it infected with a virus but when run it installs a virus into memory on to the disk, or onto a file. Droppers have been written sometimes as a convenient carrier for a virus and sometimes as an act of sabotage.
Hoaxes
There must be very few people on email who haven’t received a chain letter with the subject line warning of a virus doing the rounds. These are often hoaxes and meant to scare people and have fun at their expense. The warnings encourage the recipient of the e-mail to pass the warning to the netizens and thus create an unnecessary furor, besides clogging mailboxes, as it usurps an air of credibility.
Methodology of virus detection applied by antivirus softwares:
Three main methods exist for detecting viruses: integrity checking (also known as checksumming), behavior monitoring and pattern matching (scanning).
Integrity checking
Antivirus programs that use integrity checking start by building an initial record of the status (size, time, date, etc.) of every application file on the hard drive. Using this data, checksumming programs then monitor the files to see if changes have been made. If the status changes, the integrity checker warns the user of a possible virus.
However, this method has several disadvantages, the biggest being that false alarms are altogether too common. The records used by checksumming programs are often rendered obsolete by legitimate programs, which, in their normal course of operations, make changes to files that appear to the Integrity checker to be viral activity. Another weakness of integrity checking is that it can only alert the user after a virus has infected the system.
Behavior monitoring
Behavior Monitoring programs are usually terminate and stay resident (TSR) and constantly monitor requests that are passed to the interrupt table. These programs are on the lookout for activities that a virus might engage in–requests to write to a boot sector, opening an executable program for writing, or placing itself resident in memory. The behavior these programs monitor is derived from a user-configurable set of rules.
Pattern matching
Using a process called “pattern matching,” the anti-virus software draws upon an extensive database of virus patterns to identify known virus signatures, or telltale snippets of virus code. Key areas of each scanned file are compared against the list of thousands of virus signatures that the anti-virus software has on record.
Whenever a match occurs, the anti-virus software takes the action the user has configured: Clean, Delete, Quarantine, Pass (Deny Access for Real-time Scan), or Rename.
Self Defense Mechanisms Evolved By Viruses
Virus authors of course wish that their child successfully lives. For this reason there are many viruses outfitted with some self-defense mechanisms against anti virus systems.
Passive Defense :
Viruses use a variety of methods to hide themselves from antivirus programs. Passive defense uses programming methods which make analysis of the virus more difficult, e.g. polymorphic viruses which were developed to counter scanners looking for constant strings of virus code.
Today antivirus systems are capable of analyzing polymorphic code and searching for virus identifiers in the decrypted body. The virus authors reacted by making the encryption too complex for antivirus software to unravel, thus mistaking it for a clean program.
Active Self-defense :
Viruses actively defend themselves by protecting their own code or by attempting to damage antivirus software. A simple method is to locate antivirus software databases and amend or delete them.
More sophisticated resident viruses use stealth techniques. When they detect a request to use an infected file, they can temporarily “clean” it or report its original (uninfected) parameters. They can monitor which programs are being executed and react if it is antivirus software. The list of such reactions is endless. Usually, the execution of the antivirus program is refused, but it could be erased (often accompanied by a bogus error message) or the virus suspends its activities while it runs. There are occasionally extremely ‘clever’ viruses which modify the code of a specific AV program to partially disable it.
There are very rare viruses which consider an attempt to run an anti-virus program as arrogant and immediately reply with some revenge action – for example hard disk formatting.
Trap
A trap is the most malicious form of self-defense and works as follows. Although the user’s computer is infected but everything appears to work correctly. Once the user discovers the virus and removes it things get complicated – programs no longer run properly or the hard disk may become inaccessible even when booting from a clean system diskette.
The best known trap virus is One_Half. It continuously encrypts the data on a hard disk (two tracks on every boot). If it is removed from the partition sector before data files are decoded then some files will become inaccessible. At this stage the situation is serious but recovery of the data is still possible. However, if the user runs a disk utility (Scandisk etc.) to repair the damage then the data will almost certainly be lost forever.
These utilities are designed to repair relatively minor damage to file system and do not recognize the encrypted data.
REFERENCE:
1. Mary Landesman “What is a virus?”

http://antivirus.about.com/cs/tutorials/a/whatisavirus.htm

2. NetGuide “What are computer viruses? “–

http://www.netguide.co.nz/knowhow/tutorials/print.php?iid=38

3. Marshall Brain “How Computer Viruses Work”
http://www.Howstuffworks How Computer Viruses Work.htm
4. AVG Anti Virus Free Edition Help
Developed by Grisoft Inc
5. Norton Anti-virus Help
Developed by Symantec Corporation
6. Trend Micro PC-cillin Help
Developed by Trend Micro Inc
7. Peter Norton “Computer Viruses”
Introduction to Computers, Tata McGraw Hill Co:
8. Dr.Solomon ”About Viruses” &”Virus Prevention”
Dr.Solomon’s Virus Encyclopedia, Dr.Solomon’s Software Ltd.
9. C.A.Schmidt ”Virus”
The Complete Computer Upgrade And Repair Text Book,Dreamtech
10. S.Jaiswal “Virus Detection And Elimination”
Information Technology Today, Galgotia Publication Pvt. Ltd.

Today, many people rely on computers to do homework, work, and create or store useful information. Therefore, it is important for the information on the computer to be stored and kept properly. It is also extremely important for people on computers to protect their computer from data loss, misuse, and abuse. For example, it is crucial for businesses to keep information they have secure so that hackers can’t access the information. Home users also need to take means to make sure that their credit card numbers are secure when they are participating in online transactions. A computer security risk is any action that could cause lost of information, software, data, processing incompatibilities, or cause damage to computer hardware, a lot of these are planned to do damage. An intentional breach in computer security is known as a computer crime which is slightly different from a cypercrime. A cybercrime is known as illegal acts based on the internet and is one of the FBI’s top priorities. There are several distinct categories for people that cause cybercrimes, and they are refereed as hacker, cracker, cyberterrorist, cyberextortionist, unethical employee, script kiddie and corporate spy. The term hacker was actually known as a good word but now it has a very negative view. A hacker is defined as someone who accesses a computer or computer network unlawfully. They often claim that they do this to find leaks in the security of a network. The term cracker has never been associated with something positive this refers to someone how intentionally access a computer or computer network for evil reasons. It’s basically an evil hacker. They access it with the intent of destroying, or stealing information. Both crackers and hackers are very advanced with network skills. A cyberterrorist is someone who uses a computer network or the internet to destroy computers for political reasons. It’s just like a regular terrorist attack because it requires highly skilled individuals, millions of dollars to implement, and years of planning. The term cyperextortionist is someone who uses emails as an offensive force. They would usually send a company a very threatening email stating that they will release some confidential information, exploit a security leak, or launch an attack that will harm a company’s network. They will request a paid amount to not proceed sort of like black mailing in a since. An unethical employee is an employee that illegally accesses their company’s network for numerous reasons. One could be the money they can get from selling top secret information, or some may be bitter and want revenge. A script kiddie is someone who is like a cracker because they may have the intentions of doing harm, but they usually lack the technical skills. They are usually silly teenagers that use prewritten hacking and cracking programs. A corporate spy has extremely high computer and network skills and is hired to break into a specific computer or computer network to steal or delete data and information. Shady companies hire these type people in a practice known as corporate espionage. They do this to gain an advantage over their competition an illegal practice. Business and home users must do their best to protect or safeguard their computers from security risks. The next part of this article will give some pointers to help protect your computer. However, one must remember that there is no one hundred percent guarantee way to protect your computer so becoming more knowledgeable about them is a must during these days. When you transfer information over a network it has a high security risk compared to information transmitted in a business network because the administrators usually take some extreme measures to help protect against security risks. Over the internet there is no powerful administrator which makes the risk a lot higher. If your not sure if your computer is vulnerable to a computer risk than you can always use some-type of online security service which is a website that checks your computer for email and Internet vulnerabilities. The company will then give some pointers on how to correct these vulnerabilities. The Computer Emergency Response Team Coordination Center is a place that can do this. The typical network attacks that puts computers at risk includes viruses, worms, spoofing, Trojan horses, and denial of service attacks. Every unprotected computer is vulnerable to a computer virus which is a potentially harming computer program that infects a computer negatively and altering the way the computer operates without the user’s consent. Once the virus is in the computer it can spread throughout infecting other files and potentially damaging the operating system itself. It’s similar to a bacteria virus that infects humans because it gets into the body through small openings and can spread to other parts of the body and can cause some damage. The similarity is, the best way to avoid is preparation. A computer worm is a program that repeatedly copies itself and is very similar to a computer virus. However the difference is that a virus needs o attach itself to an executable file and become a part of it. A computer worm doesn’t need to do that I seems copies to itself and to other networks and eats up a lot of bandwidth. A Trojan Horse named after the famous Greek myth and is used to describe a program that secretly hides and actually looks like a legitimate program but is a fake. A certain action usually triggers the Trojan horse, and unlike viruses and worms they don’t replicate itself. Computer viruses, worms, and Trojan horses are all classifies as malicious-logic programs which are just programs that deliberately harms a computer. Although these are the common three there are many more variations and it would be almost impossible to list them. You know when a computer is infected by a virus, worm, or Trojan horse if one or more of these acts happen:

Screen shots of weird messages or pictures appear.

You have less available memory then you expected

Music or sounds plays randomly.

Files get corrupted

Programs are files don’t work properly

Unknown files or programs randomly appear

System properties fluctuate

Computer viruses, worms, and Trojan horses deliver their payload or instructions through four common ways. One, when an individual runs an infected program so if you download a lot of things you should always scan the files before executing, especially executable files. Second, is when an individual runs an infected program. Third, is when an individual bots a computer with an infected drive, so that’s why it’s important to not leave media files in your computer when you shut it down. Fourth is when it connects an unprotected computer to a network. Today, a very common way that people get a computer virus, worm, or Trojan horse is when they open up an infected file through an email attachment. There are literally thousands of computer malicious logic programs and new one comes out by the numbers so that’s why it’s important to keep up to date with new ones that come out each day. Many websites keep track of this. There is no known method for completely protecting a computer or computer network from computer viruses, worms, and Trojan horses, but people can take several precautions to significantly reduce their chances of being infected by one of those malicious programs. Whenever you start a computer you should have no removable media in he drives. This goes for CD, DVD, and floppy disks. When the computer starts up it tries to execute a bot sector on the drives and even if it’s unsuccessful any given various on the bot sector can infect the computer’s hard disk. If you must start the computer for a particular reason, such as the hard disk fails and you are trying to reformat the drive make sure that the disk is not infected.

Let’s face it for many being on the computer is hassle-full. Being on the computer isn’t fun and productive any more.

Whether your home or business computers are online or offline over time they seem to slow down and many times crash. Being on the computer isn’t fun and productive any more. What is it that

causes these problems?

It’s my experience that the average individual knows a lot about his/her chosen field and very little about computer repair services and protecting information stored on a home or business computer.

Most of us are looking for a simple easy way to work or play on our computer. Unfortunately, computers have become complicated, necessary tools. Yet, it seems, several months after purchasing a computer it begins to bog down and run slower. You might experience mysterious freeze ups and crashes. Once this problem turns into a nuisance, generally, the computer is taken into a computer repair service shop where it will be out of commission for a week or so and a few hundred dollars spent to clean it up.

Most people don’t understand the relationship between a slow running computer and cyber-crime. Yet, the relationship is huge. There is a huge need to develop safe computer practices and rely on

an emerging computer industry called “Personal Computer Services.”

One of the ways I like to describe computer safe practices is by comparing it to safe dental practices. We are encouraged to develop an everyday practice of flossing and cleaning teeth, right? We do this to keep the teeth clean and avoid dental problems like infection and tooth decay in the future. In other words we do this to avoid dental hassles. We want a hassle-free dental experience.

Now, when you compare best dental practices to keeping your computer running like new, you need to implement similar measures. Only this time instead of brushing and flossing you have to develop safe computer practices including purchasing the computer repair service money can buy. On top of that, you’ll also need to set up a safe practices guideline for everyone in your family.

A slow running computer or a computer that crashes frequently may be a sign of Malware (Trojans, viruses, worms, and other malicious code) on your computer. These hacker tools not only can be used to steal sensitive information from your computer they slow your computer down or even cause computer crashes. Unfortunately, traditional over-the-counter computer protection products don’t keep up with this growing problem. If they did would we continue to have these problems?

Over the last three years there’s been a huge shift from curious hackers to professional hackers creating devious methods to steal proprietary information from computers like yours. This evolving threat is costing individuals and businesses tens of billions of dollars every year. V. McNiven, an advisor to the U.S Department of treasury has stated, “The proceeds from cyber-crime are now greater than the sale of illegal drugs.

These evil hackers continue to find more devious ways of stealing financial and proprietary information. It is important that every individual, family and business have a computer repair service plan in place to protect themselves from these cyber terrorists.

You might be surprised to learn that computers that don’t go online are vulnerable through file sharing from infected flash drives, cds and floppies. These devices, when infected, can install scrambling software or logic bomb software that opens up the possibility of extortion to get your proprietary information back.

A 2007 PC Magazine survey of 42,000 PCs worldwide released last September showed the top speed killers. The problems included:

· Over 52 percent of the PCs surveyed were clogged up with spyware

· Over 60 percent of the PCs surveyed had un-optimized Internet settings slowing the Internet down and even signaling that spyware and other malware have secretly stolen portions of your bandwidth to run on your PC.

· Surveyed computers also contained an average of twelve serious registry problems per unit that may have been caused by spyware and other malware.

Incredible, many of these computers are supposedly protected by the over-the-counter products that aren’t doing what they promise to do. So how can individuals and small businesses protect against identity theft, fraud and extortion? How can they get their computers back to running like new again?

Here are six crucial steps to protecting your computer and making it fun and productive again:

1. Keep your computers patched. Microsoft has automatic patch updates. Make sure are signed up to receive them.

2. Use professional enterprise grade anti-virus and anti-spyware at the email and web gateways. Install a professional grade by-directional firewall to guard against backdoor threats.

3. Use sender-authentication technologies, such as Sender Policy Framework (SPF) to make phishing far more difficult since – In theory – phishers will only be able to send their spam from “unapproved” domains.

4. Develop and enforce a password policy. This will make passwords difficult to be guessed. Use a different password for each situation. Make sure these passwords are changed frequently. If you use one password for every web site, for example, and a phisher manages to steal it, all of your online activity is at risk. Sophos, an enterprise grade Internet Security Company, recently conducted a business poll and discovered 41 percent of the respondents were using the same password for all web sites.

5. Keep an eye on the advice from organizations promoting safe computing. Many of their web sites will list the latest threats, and give advice on how to protect your home and business against them.

6. Always report suspicious activity.

Just as important, find a computer repair service that offers “Personal Computer Services.” Your personal computer service should include online repair at no additional cost. The end result: hassle-free computing making being on the computer fun and productive again. With the right computer repair service, using computers at home and at work should be hassle-free allowing you to focus more on your home and business activities.

As a computer master, I got inquired on how to fix computer errors all the time . Now I can get into a long word about what types of errors they are experiencing and what manual steps they can take, but that would be too much difficulty. So my advice is to do something that is way easier and far more effective.You may have not ever heard of the term registry; however it plays a vital role in the functionality and operation of your computer. Generally, if your system’s registry is full of errors you are likely to suffer a decrease in performance and more likely at some point you’ll start to see the annoying errors popup, your best choice is to run a registry cleaner software to fix errors on computer because you surely don’t want to get a low-performance computer.One of the leading features of the best registry cleaners is the power to compact and optimize your computer’s registry. Over time, the registry gets fragmented and corrupt due to new program installations, the uninstalling of old programs, updates, etc. What the registry cleaner will do is removing unnecessary entries and compact everything else, therefore, as your computer searches through the registry when booting or attempting to launch programs or perform any other tasks, it will find what it needs much faster. This results in boot time and application startup times being reduced sometimes by over 50%.So with a rated registry cleaner, not only will you fix computer errors that are getting you headaches, but you’ll also benefit from speeding up your computer to the point where it runs almost as if it were new again.

As a computer master, I got inquired on how to fix computer errors all the time . Now I can get into a long word about what types of errors they are experiencing and what manual steps they can take, but that would be too much difficulty. So my advice is to do something that is way simpler and far more effective.You may have not ever heard of the term registry; however it plays a essential role in the functionality and operation of your computer. Generally, if your system’s registry is full of errors you are likely to suffer a decrease in performance and more likely at some point you’ll start to see the annoying errors popup, your best choice is to run a registry cleaner software because you surely don’t want to get a low-performance computer.You can invest in registry cleaning software for around $30, and in doing so you are going to gain some additional benefits besides simply cleaning up and getting rid of those computer error messages.One of the leading features of the best registry cleaners is the power to compact and optimize your computer’s registry. Over time, the registry becomes fragmented and corrupt due to new program installments, the uninstalling of old programs, updates, etc. What the registry cleaner will do is removing unnecessary entries and compact everything else, therefore, as your computer searches through the registry when booting or attempting to launch programs or perform any other tasks, it will find what it needs much faster. This results in boot time and application startup times being reduced sometimes by over 50%.So with a rated registry cleaner, not only will you fix computer errors that are getting you headaches, but you’ll also benefit from speeding up your computer to the point where it runs almost as if it were new again.