If you get yourself in the unfortunate position of having changed the privileges of Administrator such that you can no longer log in as Administrator either locally or as a service… check this out!
There is a way around, given that you’ve got another Windows machine you can put the hard drive into. Warning: this procedure is not supported by Microsoft, so I can’t promise it won’t damage the system. However, if you’re about to format the disk anyway …
Get the broken drive out of the machine and get it into an enclosure or something. Boot your “working” fix-it machine with the broken drive attached.
First make a backup copy of the contents of \windows\system32\config from the damaged system.
Run regedit, click on HKEY_LOCAL_MACHINE and then select Load Hive from the File Menu. Select the file named “system” from the folder \windows\system32\config on the damaged system. Name the key xxx (or whatever, doesn’t matter really).
Open the xxx key, then the Setup key inside it. Change SetupType to 2. Change CmdLine to cmd.exe. Shut down and boot to the original system. You should get a command window from which it should be possible to run ntrights or gpedit.msc.
This definitely just saved the day at work!!!