There should also be another error before the 0029 error, which is simply a message about the backout of the install process.
You may be able to resolve this easily by using the cleanup tool -- http://forums.microsoft.com/WindowsOneCare/ShowPost.aspx?PostID=828910&SiteID=2
If you can provide the other error code, we may have more suggestions.
You can also contact support, if desired -
How to reach support - http://forums.microsoft.com/WindowsOneCare/ShowPost.aspx?PostID=2421771&SiteID=2
If it fails to validate your subscription, select the option that you are using a trial or beta copy and you can proceed to email support without validation once you've signed in.
-steve