Two Spyware Risks
4. Often if you are prompted to “click here” by a pop up, it’s seeking you to activate a spyware download. Never do this, and don’t go to the site where it happened. Your browser should have settings that can be changed to disallow pop ups.
5. File sharing and peer to peer (P2P) programs link multiple users to each other to allow for software, data, music, movies, and nasty spyware to easily travel from one computer to another. You’ll probably enjoy the free content you’ve received, but in the background it’s likely you’ve picked up any number of extra programs leaching away your computer power, or worse. Total avoidance of these is the only way to remove the risk of spyware.
Source: www.webdefenders.net