You posted this to the Abuse reporting link and not the forum, so I moved it to the Install and Activate topic.
When you install OneCare and choose to subscribe, you need to log in with a LiveID. If you don't have a LiveID you can create one - http://account.live.com
Since you signed into these forums, you have a LiveID, which may be your email address. If so, then the only reason that signing in would tell you that the password is not correct is if your password is longer than 8 characters. That's a bug in the activation process (or it was). So, try changing your LiveID password at http://account.live.com
If that doesn't help and you are still unable to activate, please contact support.
How to reach support (FAQ) - http://forums.microsoft.com/WindowsOneCare/ShowPost.aspx?PostID=2421771&SiteID=2
-steve