Have a customer that has 2 NT 4 servers. 1 server is the PDC of the domain. This server only functions as the PDC and does not need to remain on the network. There is also no desire from the customer to upgrade this server to 2000. The 2nd was astand alone server that I upgraded to Windows 2000. On the 2000 server I need to upgrade Exchange 5.5 to Exchange 2000. In order to upgrade Exchange, the 2000 server needs to be running Active Directory. Is there any way to run Active Directory on the 2000 server under the NT 4 domain? I want to keep all the NT 4 Domain settings in tact. Can I setup the 2000 server with the existing domain settings while the NT PDC is down? Then bring up the NT server and demote it to a BDC? Any suggestions to accomplish this would be greatly appreciated. Remember that the NT 4 PDC server can Disapear after the 2000 server comes up as the Domain Controller. It does not run anything needed for this company and can therefore be brought down after the 2000 server assumes Domain COntroller.