Spybot S&D 1.3. Ive heard lots of good about it and I have used it before. It is good. Get it
here.
I heard Ad-Aware gets the rest of what SpybotS&D misses. Havent tried it yet but heard lots of good for this too. Get it
here. Then after install, use the webupdate function to get the latest file updates for Ad-Aware.
I hope this helps.