Spybot and Stopzilla won't help if your infected with a virus.
Try running malwarebytes and then try to install AVG free or Kaspersky (demo). If AVG or Kaspersky will not install at all, then I'd bet pretty much that you are infected. When anti-virus apps like Kaspersky lock up during the install, it is typically the dead giveaway that your infected.
If so, consider getting on a clean system and download the Kaspersky rescue disc iso and burn it to a cd ... then boot the problem system, run the virus definition update and scan your system. I've had really good results with it in the field.
KIS 10 Rescue Disc