If the methods in this post don't help -
http://social.microsoft.com/Forums/en-US/onecarebackupandrestore/thread/f0281206-ed0b-474c-8541-cc50843e5be2 you can format the drive if there is no other data on it that you might need.
Jim
Microsoft MVP Consumer Security - Forum Moderator - Live One Care - Live Mesh - Microsoft Security Essentials