Vista - xp root drive permissions messed up

Hello!

Greetings everyone.

I installed xp (sp2 DIY streamlined) inside drive E: ;
and vista (home premium) in C: .

After I booted into vista, I decided to sort things out ;P so I simply rename/label drive E: to WINXP (since xp os inside), then the system warns and requires my permission and I allowed.

Haha, since then, everytime I boot into xp, the system halt at the login screen, with NO accounts to choose and the screen keep flashing every now and then.

I tried to boot in vista and checked user permissions for E: drive at right-click>property>security, compared to another pc and found that one user (unknownS-1-5-32-547) is missing, I guess this is the problem but not sure.

Seems I cannot edit that unknown userS-1-5-32-547 to full control E:, as I propably REMOVED it when I label the drive, can I? (as inside vista, it is not available to be added as a new user)
Can I somehow extract and import all users from xp to vista, and then add the user to full control E: ?
Any hints are welcome.


Many thanks,
Harry