Windows 2000 log in problem: made 1 change and now I am stuck.

I have a old system running windows 2000 that has some custom made monitoring software for our machines in our plant. When the machine loads it has always said "Administrator" in the username box and the password was always blank, so you would hit enter and it would load up. I decided today to disable needing to login so in the advent of the machine restarting itself it would auto load into windows and the monitoring software would auto load. So I went into the control panel, users and disabled, changed to auto login no password etc. Rebooted and now I am confronted with a "system could not log you on. make sure your user name and domain are correct, then type your password again" message. Of course there never was a password to begin with, I always had left it blank, so hitting enter, etc keeps cycling this message. Now I can't even get back into the system and seem completely locked out just from the simple change.

Does anyone know why it did this, or any way around it? Everything in here is custom programmed and the guy who made it and tweaked it passed away.

Thank you!

Mark

I would try logging in with safe mode and re-enable the login or run system restore from there.