Accounts :: Hidden Administrator Cannot See Main Local Account

For one reason or another I managed to delete administrator privileges for my one local account. After several hours messing about I have managed to activate the hidden Administrator - but I am finding that this Administrator is not working.

1. It cannot see my main local user account. It does not list it at all in User Accounts, so I cannot change any settings etc. Similarly, when I open User Accounts with my main account, it cannot see the Administrator, or the new account I created (see below)

2. When I access User Accounts using "netplwiz" it sees my main account but will not highlight it (or any other account). It is stuck on Administrator.

3. It will not create a new account. When I use it to access Accounts and try to add a new user the cursor spins and nothing happens.

4. I added a new user (with administrator privileges) using the command prompt - this was successful, but it bumped my main account off the login page, and it doesn't acknowledge it on the dropdown list with the start menu. (Yet when I restarted it took me straight in to my main account.)