You start unloading stuff from them (Start Button, Settings, Control Panel, Add/Remove Programs), and they direct you to a web site that asks if you really want to do this, then you have to download something to remove the stuff.
Then later, you go to remove some other unknown thing (I think I remember it started with a 'P'), and you are again taken to their web site to again download, and 'really' remove their stuff this time...
I fixed the problem by downloading the AD AWARE by LAVASOFT. It pointed out a lot of spyware that my virus checkers ignore. It seems thorough and informative, although I only have a few day's experience with it...