It sounds like your PC may have been infected.
This forum is dedicated to Microsoft Security Esentials Beta
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
Microsoft MVP Windows Live / Windows Live OneCare, Live Mesh, & MS Security Essentials Forums Moderator