Is your password longer than 8 characters? If so, shorten it at
https://account.live.com and try again.
If not, please contact support for assistance.
use the option as a trial user to start an email case...
How to reach support (FAQ) - http://social.microsoft.com/Forums/en-US/onecareinstallandactivate/thread/30400b52-7f26-4ba0-bc18-17e305329d90
-steve
Microsoft MVP Windows Live / Windows Live OneCare, Live Mesh, & MS Security Essentials Forums Moderator