I am currently in malware hell, and it sounds like what you've been describing here. It happened to both my home pc and my work laptop, both of which I was using Sunday on Facebook. (Not sure how... I don't remember clicking any links.)
My laptop is being reimaged, but it's my home pc that is out of control. I have popups for both Antivirus 2009 and Spyware Guard 2008. Whenever I try to visit a site to download programs for removal, I'm redirected to their own bs antivirus sites.
My latest attempt has been to download the programs on another computer, and copy them to the infected pc. The executable files copy correctly, but none of them will open. I've tried Malwarebytes Anti-malware, STOPzilla, and now SAS.
Any help on how to get these files to open and exectute??