locked out of admin rights

hi,

please can someone help?
I have locked myself out of admin rights and hidden the only admin so now I can't adjust the setting or login to admin to fix, install anything or update!

How?
I created a registry key found through google to hide the administrator and I only wanted to use std users.

System restore. If fail, system repair.

Better yet, provide the contents of the reg tweak.

Should have just disabled the Adimistrator account thought the User & Groups in Computer Mangament. That is how it is by default.