Cannot log on as Administrator

Hi Guys, Just installed SD+ (build 7506) for the first time, only a small company and I'm the only tech so I installed the Free Standard version.

I remember setting up the config to not let users log on locally, only through their domain, now that I have logged out I cannot log back in as the Administrator!

Whenever I use the username 'Administrator', click into the password field it shows in the 'log onto' field as "Domain Not Found", and wont allow me to log on.

I haven't set up any other administrators other than myself, with the log on 'Administrator'.

I tried to log onto the host server as local admin, no luck though, seems everything I try doesn't work, any ideas???

Thanks, Scott.