Try the Virus and Spyware repair tool - http://forums.microsoft.com/WindowsOneCare/ShowPost.aspx?PostID=2667445&SiteID=2
If this doesn't work, please contact support -
How to reach support (FAQ) - http://forums.microsoft.com/WindowsOneCare/ShowPost.aspx?PostID=2421771&SiteID=2
-steve