I've tried spyware programs by the dozens (free and paid). Name it, I've tried it.
Until I came across SpyNoMore: http://www.spynomore.com
There's no way for me to come back to any other spyware software (and there are some quiet good ones out there). Show any "clean" PC to SpyNoMore and it will find - and remove - dozens and dozens of spyware, malware, highjackers, dialers, trojans, backdoors, downloaders, etc.
Don't take my word for it. Clean your computer with any good spyware software, and then give the other one a try.