You'll need to resolve the Brave Sentry issue. You can seek help from Microsoft -
If you are in North America, you can call 866-727-2338 for help with virus and spyware infections. See http://www.microsoft.com/protect/support/default.mspx for details.
For international information, see your local subsidiary Support site.
or contact OneCare support - use the option that says you are using the trial software to start an email support case.
http://help.live.com/help.aspx?project=onecarev2 - use the "Get More Help" link in the lower right of the page to contact support
-steve