i usually use no antivirus programm for my pc. if i go in the www, i use linux.
i use windows only for games and other programms, and my printer, because there are no drivers for linux^^ i save my ressources for the games. today games need alot of ressources, for exaple GOTHIC 3
But if you are looking for real protection i can only say that the best for you will be Kaspersky Anti Virus Personal 6.0. It is not cheap!But the trial version is also ok to use.you can download it from www.downloads.com For free of course!
the trial version is only for 30 days...
30 days of perfect protection from all kinds of spyware Trojans,helckern,different worms...