afaik, when the documents folder is set to private, its set to private
that means no external acces from anywhere but the account that its locked to...
otherwise - download and get going a copy of UBCD (http://ubcd.sourceforge.net/
) or alternatly, recovery console.
boot into it, load up cmd:
(where x is, replace with your drive letter, also assumes you use the administrator account)
cd x:\documents and settings\user
cacls "my documents" /g administrator:f
of course if u cant get into the users folder, make it cacls user /g administrator:f
as i said, im pretty sure that if its private, it is really private...