Yeah, computers are added to the domain through a user account. The user account is simply the computer's NetBIOS name. When it connects for the first time, it changes the password and remembers it. I can think of two options for you to do. First is to copy the sam database. I can't remember which file it's in though. Second is to reestablish the computer accounts. On the domain controller, you'll have to delete the computers from the domain and readd them. You may have to tell the workstation computers to leave the domain too and then rejoin them. If you have a lot of computers, this is a whole lot of work.