Welcome to the board.

No good news for you here for NT/2k machines.

Unfortunately, machine names are part of the SID (Security IDentifier).

You will have to do the following:
Pull the machine(s) out of the domain.
Restart..
Rename to a "unique" name.
Restart..
Add the machine back into the domain using a Domain Admin Account..
Restart..

Kinda tedious huh?

Sorry.

- Kent