Simple solution....It's been said, use firefox & not IE. I use Kaspersky Anti-virus, it's been the best. It even will catch a program trying to copy hidden programs somewhere else (i.e., spyware), also blocks registry changes unless you let it.
Edit: P.S. with these two programs, I've never had to use anything else, like ad-aware or whatever anti spyware blocking prgram anyone uses.