I helped a friend build a new PC and freshly install XP Home and he's asking me what I recommend for PC Protection.

At this time, I'm not sure what to advise him.

I installed AVG on my PC last year, but I've been told that it's been problematic in recent versions.
What is the latest free anti-virus (not trial ware please).
I already installed Adware, Spybot S&D and SUPERAntiSpyware.

I saw WOT and I'm thinking about installing that as well.