You should contact support for help with this.
How to reach support (FAQ) - http://social.microsoft.com/Forums/en-US/onecareinstallandactivate/thread/30400b52-7f26-4ba0-bc18-17e305329d90
You may want to try the database reset tool -
http://www.microsoft.com/downloads/details.aspx?FamilyID=4bc2594b-95ab-4235-b5b8-41656b38480f&DisplayLang=en or a reinstall of OneCare, but both of these will require you to reconfigure any options you have set up.
-steve
~ Microsoft MVP Windows Live ~ Windows Live OneCare| Live Mesh|MS Security Essentials Forums Moderator ~