What is a virus? A computer virus is an unwanted (though not always mischievous) program that is loaded by and runs on your computer without your knowledge or permission.
Viruses are written by computer programmers to challenge themselves and to explore capabilities of both their software and computers. Some viruses are innocent, simply displaying a word or playing a sound. Other viruses (the ones we all are afraid of) can be extremely destructive, and can erase or corrupt a hard drive or disable an entire corporate network! Viruses (both in real life and digitally) have to be able to reproduce or replicate themselves.
Your computer can only get a virus by executing, running or opening an infected program. This is often done accidentally (with an executable e-mail attachment) or by running a downloaded program or booting from an infected disk. You can't get a virus by just being on-line or reading e-mail.
Many of the problems with a computer are blamed on viruses, when in fact they are software incompatibilities with the operating system (however subtle), software bugs, or operator error. Most of these are not destructive.
Here are some tips for protecting yourself:
For information on current viruses and alerts.
Here are some downloadable anti-virus software packages (not all good software can be downloaded from the Internet).