Kanute78, the behavior you describe is also identical to a virus or Trojan that was going around a few years ago. It would get onto your PC, and then when you tried to click top search results, it would redirect you to sites selling bogus stuff. Please do some deep virus scanning to make sure you're safe!
(What they discussed in the other thread is a little bit different, and that's why I'm bringing this up. Many people had this bit of malware for quite a while before realizing it, so I just wanted to let you know about it.)