Search Engines Redirect me to Spam Sites and Random Sites

I have IE(latest version) Firefox(3.07) and Google Chrome. When i go on Firefox, or IE, or GC, and go to either Yahoo or Google search engine, and search something, and CLICK the link, it redirects me to random websites, usually YellowPages. If i copy and paste the link off of Google and put it in my address bar, it takes me to the site just fine. I contacted my ISP for assistance, and they decided that it wasn't a virus. They had me Reset IE, and IE works again, with searching. Google Chrome works again. But, Mozilla doesn't They had me uninstall Mozilla, and reinstall it, and it was still the same problem. Can anyone help me? My computer HAS been going a little bit slower than usual, so i hope it isn't a virus. Any help would be appreciated, thanks.

You should take the system through the Virus and Malware Cleaning, attach the three logs and get help with the entries.

Instructions here: http://www.techspot.com/vb/topic58138.html

Redirects are usually due to malware.

Thanks, i tried to download a few of the programs in the 8-step list, and this virus that i have doesn't let me download ANYTHING. Can anyone please help?

Which one of the three browser you have is set as the default?