Have you scanned your computer with your AV or any Anti-Spyware program lately?
Download,update and scan with AVG-Antispyware(a free product)http://www.ewido.net/en/product/
Or you could run Windows Live Onecare Free Scanhttp://safety.live.com/site/en-us/default.htm
It will say "Get a free PC safety scan". Make sure you click "Full Service Scan" in the middle of the page and
not the "Try It Now Free" on the right side.
Allow it to download an Active X component.
Choose "Complete Scan" in the window that opens. Click "Next"
Allow it to scan - it may take quite a while, maybe two hours or so depending on how big your hard drive is and how fragmented your registry and drive are.
See if that resolves the problem.