Hello j.cullen,
Unfortunately, the issue seems more Permissions related then Activation so this forum may not be the best place to get help.
If none of the community posters, in this forum, have any advice for you, I would recommend posting in the "Security, Privacy, and User Accounts" section of the Windows XP forum at
http://social.answers.microsoft.com/Forums/en-US/category/windowsxp
Sorry I couldn't be more help,
Darin MS