I agree with the multiple product approach the most. No one product catches everything. My arsenal is like this. Ad-aware (free-don't waste the money to buy the pro edition), Spybot S&D, then Hijack this if it is still there. The latter takes a little experience because it will let you remove things that are needed for other applications, but it can also clean up a lot of things that NO product can touch. There are a lot of spyware forums that will take Hijack this logs and give you advice if you've got a really nasty bug.