Re: I agree with Scott - AVG has been fantastic.
My only beef with AVG is the way it updates itself. It does it often, which is good of course, but its pops up windows, does the update, doesnt close the windows immediately. its pretty "loud". I guess that's good in a way, but i like a less intrusive program.
I have three windows boxes (2 XP and 1 Vista). I use AVG, Symantec Corporate (work machine), and my desktop machine uses Nod32. My favorite of the group. I will probably change the AVG on the Mac/Windows to Nod32 soon. It costs $40, not cheap but ok.
There are other options too. You might check with your ISP. Comcast used to give away McAfee, my stock trading company (Scottrade) gives it away to their customers. AOL gives one away as well.
(Dick Bartley [LM-5316-201 Connecticut]) 
My experience with Norton's... 
