If you have One Care installed on another computer you can open One Care>Help>About Windows Live One Care and you will see the Live ID associated with your subscription. If you do not have One Care installed on another computer or if you cannot remember
the correct password you can contact support for help. How to reach support -
http://social.microsoft.com/Forums/en-US/onecareinstallandactivate/thread/30400b52-7f26-4ba0-bc18-17e305329d90
Jim
Microsoft MVP Consumer Security - Forum Moderator - Live One Care - Live Mesh - Microsoft Security Essentials