I have used AVG and Spybot for a good 7 to 8 years now and never had a virus. Touchwood. I recommend both to all my friends and no one i know has ever had any problems with them.
Norton on the other hand i would stay well away from..
2012 FFL WINNER
2013 FFL TEAM
Demetrious Johnson ~ Nate Marquardt ~ Hector Lombard ~ Michael Bisping ~ Jimi Manuwa
UFC 41-27-2 Strikeforce 10-4