Check out the stickies below for lots of info & links to AV & security programs. As well as an AV (Antivir PE), I use Spybot S&D, Ad-Aware, PeerGuardian2 & AVG Antispyware (formerly Ewido). Of course, everyone uses different things

WARNING: Viruses on the network you should be aware of

http://www.gnutellaforums.com/showthread.php?t=58603

Make sure that you scan downloaded files before you open them.