Viruses and worms have the potential to destroy countless hours of your work and because of the way they propagate, you risk endangering the work of your professors and friends too. It is good to learn what viruses are and what to do to protect yourself.

What Is A Computer Virus?

Computer viruses are small software programs that are designed to spread from one computer to another and to interfere with computer operation.

A virus might corrupt or delete data on your computer. Most viruses spread by reproducing themselves when the attachment that contains them is opened. The most common type finds your address book and sends messages with an infected attachment to all the addresses listed there. While some viruses do as little as disable printing, others can cause your computer to fail completely, or destroy the data on your hard-drive.

Viruses are most easily spread by attachments in e-mail messages or instant messaging messages. That is why it is essential that you never open e-mail attachments unless you know who it's from and you are expecting it.

Viruses can be disguised as attachments of funny images, greeting cards, or audio and video files.

Viruses also spread through downloads on the Internet. They can be hidden in illicit software or other files or programs you might download.

Any type of computer can be attacked by a virus. Windows PCs are most often the target of virus attacks. Viruses can also attack system vulnerabilities when your computer is connected to a network such as a campus network or a dial up Internet service.

To help avoid viruses, it's essential that you keep your computer current with the latest updates and antivirus tools, stay informed about recent threats, and that you follow a few basic rules when you surf the Internet, download files, and open attachments.

Once a virus is on your computer, its type or the method it used to get there is not as important as removing it and preventing further infection.

Are You Infected?

After you open and run an infected program or attachment on your computer, you might not realize that you've introduced a virus until you notice something isn't quite right. Here are a few primary indicators that your computer might be infected:

• Your computer runs more slowly than normal
• Your computer stops responding or locks up often
• Your computer crashes and restarts every few minutes
• Your computer restarts on its own and then fails to run normally
• Applications on your computer don't work correctly
• Disks or disk drives are inaccessible
• You can't print correctly
• You see unusual error messages
• You see distorted menus and dialog boxes

These are common signs of infection—but they might also indicate hardware or software problems that have nothing to do with a virus. Unless you install and run industry-standard, up-to-date antivirus software on your computer, there is no way to be certain if your computer is infected with a virus or not.

Tip: Beware of messages warning you that you sent e-mail that contained a virus. This can indicate that the virus has listed your e-mail address as the sender of tainted e-mail. This does not necessarily mean you have a virus. Some viruses have the ability to forge e-mail addresses.

This is commonly referred to as spoofing an email address.

Even for an expert, removing a virus from a computer can be a daunting task without the help of tools designed for the job.

How to Remove A Computer Virus

Some viruses and other unwanted software (including spyware) are even designed to reinstall themselves after they have been detected and removed.

Fortunately, by updating your computer and using free, trial-period, or low-cost antivirus tools, you can help permanently remove (and prevent) unwanted software.

Steps to help remove a virus:

1. Visit Microsoft Update and install the latest updates.
2. If you currently use antivirus software, visit the manufacturer's Web site, update your software, and then perform a thorough scan of your computer. If you don't use antivirus software, use a free online scanning tool and scan your computer immediately.
   • Trend Micro's Housecall
   • Microsoft's Windows Live OneCare
   • Kaspersky - This site is a very good scanner. However, it does not remove viruses, it just shows you where they are located. You have to delete them manually, including any registry entries.
3. Download, install, and run Adaware 2007
4. Download, install, and run the Malicious Software Removal Tool (for Microsoft Windows XP or Windows 2000 users). Note that this tool does not prevent viruses from infecting your system; it helps to remove existing viruses.

Many times in order to remove a virus or spyware from your computer, you'll have to start your computer in Safe Mode. While in Safe Mode, only specific programs and files needed to run the operating system are loaded. Some functions will not be active in Safe Mode and a standard video driver will be loaded causing a washed out look and a possible change in resolution.

However, because just the essential programs and files are loaded in Safe Mode, this allows us to remove some spyware, adware, viruses and such that cannot be removed in Normal Mode. Follow the instructions below to Start Safe Mode:

• Turn the computer on or Restart the computer.
• Start tapping the F8 key. The Windows Advanced Boot Options Menu appears. If you begin tapping the F8 key too soon, some computers display a "keyboard error" message. To resolve this, restart the computer and try again.
• Ensure that the Safe mode with Networking option is selected.
• Press Enter. The computer then begins to start in Safe mode.
• Follow the steps listed above to remove the virus.
• When you are finished with troubleshooting, close all programs and restart the computer as you normally would.

How to Prevent Computer Viruses

Nothing can guarantee the security of your computer 100 percent.

You can continue to improve your computer's security and decrease the possibility of infection by using a firewall, keeping your system up-to-date, maintaining a current antivirus software subscription, and following a few best practices.

Tip: Because no security method is guaranteed, it's important to back up critical files on a regular basis before you encounter a virus or other problems.

Steps to help avoid viruses:

1. Use an Internet firewall (Note: Windows XP with SP2 and Windows Vista has a firewall already built-in and turned on by default).
2. Visit Microsoft Update and turn on automatic updating.

   Note: If you've installed Office 2007, Office 2003 or Office XP, Automatic Updates will also update your Office programs. If you have an earlier version of Office, use Office Update.

3. Subscribe to industry standard antivirus software keep it current.
4. Never open an e-mail attachment from someone you don't know.
5. Avoid opening an e-mail attachment from someone you know, unless you know exactly what the attachment is. The sender may be unaware that it contains a virus.