You're off topic for this forum, which is dedicated to Windows Live OneCare. You may want to try the Microsoft Public newsgroups here: http://www.microsoft.com/communities/newsgroups/list/en-us/default.aspx
You can also seek help starting here:
Windows Update Solution Center - http://support.microsoft.com/ph/6527
However, I suspect that your PC is infected by some sort of malware.
If you are using Windows Live OneCare and you have been infected, but OneCare did not detect or cannot remove the malware, please contact support to report this and for help with removal.
How to reach support (FAQ) - http://forums.microsoft.com/WindowsOneCare/ShowPost.aspx?PostID=2421771&SiteID=2
If you are not using Windows Live OneCare, you are off topic for this forum. This is not a general forum for viruses, spyware, or Windows Help. For help with spyware issues, you may want to try the forums here:
http://aumha.net/ For help with virus removal, contact the maker of your Antivirus program.
If you are in North America, you can call 866-727-2338 for help with virus and spyware infections. See http://www.microsoft.com/protect/support/default.mspx for details. For international information, see your local subsidiary Support site.
-steve