I also suggest spybot, hijackthis, and ad-aware personal. Warning HiJackthis will fine ALOT of "problems" on your PC they are NOT all problems "fixing" them can harm your computer badly. Have one of use analyze it for you.
I just assumed since you said you installed them.. i was like you may not really thinkg about how much spyware and things like that hurt your computer, i apologize if i am wrong.
-blitze