You did not need to remove the trial. You simply needed to activate the subscription using your Qwest Live ID as noted on the download page:
http://kai03.qwest.com/WindowsLive/MemberCenter/DownloadOneCare.aspx
You may need to download and run the cleanup tool before reinstalling:
Cleanup tool - http://social.microsoft.com/forums/en-US/onecareinstallandactivate/thread/399071e2-49dc-4767-932d-d261e3965943/
See this post for the KB article to troubleshoot install problems - http://social.microsoft.com/forums/en-US/onecareinstallandactivate/thread/ba26b781-da18-4ce4-be8c-22647bd5d8fc/
If you need help with the install or activation, Qwest provides your support - give them a call.
-steve
Microsoft MVP Windows Live / Windows Live OneCare, Live Mesh, & MS Security Essentials Forums Moderator