This may take a few tries to get it, but I'd say you definitely have a virus. Slap me if I am wrong...
1st, go to a good on-line Virus scanning site, like
this one .
If it puts a halt to this, then you will need to boot into safe mode with networking to do it. Restart your PC, after the POST screen, tap F8, F10, or whatever it takes to get to the safe mode boot screen. Choose Safe Mode with Networking. Then try going back to that site.
If still no go, you will need to boot to regular safe mode, and try getting into msconfig (type that into run box), and then look under the startup tab and disable anything that looks unfamiliar. Then try booting up into your regular account, and try again.