Safe Mode does not seem to help. I am in Safe Mode only as a Limited User. I still cannot edit User Profiles or change WinLogon in the registry. I have to get on as an Admin - but I am not given that choice!!!!
It should allow you to run regedit as the Administrator user with full privileges.
(You could also run cmd this way .. I'd probably try launching rstrui.exe to do a system restore with %systemroot%\system32\restore\rstrui.exe) -- AT&T U-Hearse - RIP Unlimited Internet 1995-2011 Rethink Billable.