What are Viruses, Malware, and Spyware ?

Malware,or malicious software, is a class of software designed specifically to wreak havoc on a computer—your computer. Malware includes such nasty entities as viruses, Trojan horses, worms, and spyware.

If you’re experiencing frequent crashing, nonsensical error messages, pop-up advertisements (other than when surfing the Web), or slower-than-normal performance, the culprit may be one of the following types of malware (as opposed to a feature authored by Microsoft):