What is a computer virus?

Computer viruses are software programs deliberately designed to interfere with computer operation, record, corrupt, or delete data, or spread themselves to other computers and throughout the Internet, often slowing things down and causing other problems in the process.

Just as human viruses range in severity from the 24-hour flu to the Ebola virus, computer viruses range from the mildly annoying to the downright destructive, and come in new and different forms. The good news is that with an ounce of prevention and a little knowledge, you are less likely to fall victim to viruses and you can diminish their impact.
How do viruses work?

Basic viruses typically require unwary computer users to inadvertently share or send them. Some viruses that are more sophisticated, such as worms, can replicate and send themselves automatically to other computers by controlling other software programs, such as an e-mail sharing application. Certain viruses, called Trojans (named after the fabled Trojan horse), can falsely appear as a beneficial program to coax users into downloading them. Some Trojans can even provide expected results while quietly damaging your system or other networked computers at the same time.

Nothing can guarantee the security of your computer 100 percent. However, you can continue to improve your computer's security and decrease the possibility of infection by keeping your system up-to-date, maintaining a current antivirus software subscription, and following a few best practices.

1.Use an Internet firewall (Note: Windows XP with SP2 has a firewall already built-in and active).

2.Visit Microsoft Update and turn on Automatic Updates.

3.Subscribe to industry standard antivirus software and 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.