Opened Bad Site

Knowing better, I tried to download a player to view a video clip from a questionable site. I immediately got a popup showing a fake virus scan taking place and lots of viruses infecting my computer and stating that I was experiencing a virus attack. The popup heading was something like "MS Security Center". Then another popup said "click here to remove viruses". Upon clicking a screen gave all the prices for the service, like $38.95 for 3 months of updates.They were willing to accept my credit card number, but I don't think that would be the grandest idea. I can only delete these popups for about 10 seconds before they come back and they're always in foreground. I tried to run my McAfee virus scan an in a very short time it locked down the firewall to all outgoing and incoming internet traffic.So I doubt I can get a HijackThis.unless I can safely disable the firewall.

I'm writing this on another computer.

Your advice would be much appreciated. Should I throw the computer in the lake, install a new hard drive and reload everything, or can y'all help me fix it.

Sincerely, Addnovice