autologon feature stopped working

I had one of our users home computer setup to autologon so he wouldn’t have to bother with it. So, he calls me saturday at home and says the computer is now asking for a password for the administrator.

Well, to make a long story short, no one remembers what the admin password is. I took his hard drive and put it in my machine and searched through the registry files looking for the autologon keys that show the plain-text password but couldn’t find it.

Does anyone know if this is possibleto search through the raw registry files and recover the autologon values of the user/password?

Thanks for any and all good ideas!