Jimbo -
Key is HKEY_LOCAL_MACHINE\System\ControlSet<0x>\Control\ProductOptionsValues in ProductType:
LANMANNT = Domain Controller
SERVERNT = Member server
Check HKLM\System\Select to determine which is the current ControlSet 9numeric value 0-2 normally).
You could also use the NT 4.0 ResKit utility 'netdom'. Run, for example, 'netdom query /domain:<my domain> pdc' and it will return the PDC. Substitute 'DC' for 'PDC' and it will return all DC's. Additionally, can use remotely against domains you have trust relationships with to see their DC's, member servers etc [netdom query /domain:<trusted domain> dc].
Bill
