Locked out!

I have hidden my all accounts in Vista with administrator privileges through the user list in the registry so only the standard account is available on the log in screen.

I cannot make changes to the registry through the standard account so am locked out. Even in safe mode this is the case.

How can I reverse this to get back into the admin account?

Thanks

Weclome
You may be able to acess system restore with this administrator. If you can make a system restore to the point before you touched the registry.
http://www.vistax64.com/tutorials/67567-administrator-account.html
http://www.vistax64.com/tutorials/76905-system-restore-how.html