http://support.microsoft.com/kb/822942 You cannot (it is unsupported) promote/demote a server which is already running Exchange 2003 to/from a DC. Beyond that, your future hardware plans are too vague to give specific advice. Your goal should be to run Exchange on a member server and leave Exchange off the DC's, if they can afford to keep two servers running when it's all done. If they can afford to keep three servers running, then you should have two DC's and one Exchange server. And your next goal after that should be to have Windows 2003 SP2 on all servers when finished. Carl _____ From: exchangelist-bounce@xxxxxxxxxxxxx [mailto:exchangelist-bounce@xxxxxxxxxxxxx] On Behalf Of Chris Wall Sent: Tuesday, July 31, 2007 4:14 PM To: exchangelist@xxxxxxxxxxxxx Subject: [ExchangeList] Upgrading Exchange 2000 to 2003 Hello all, I am researching upgrading an Exchange 2000 environment to Exchange 2003 where the Exchange 2000 server is installed on a Domain Controller. There is only one DC and only one Exchange 2000 server (same box). First thing is to get another DC (global catalog) up and running on the network. Before introducing the first Exchange 2003 server, should I run DC Promo and demote the server to a Member Server? This is my first run in with Exchange 2000 on a DC during an upgrade process - any pointers (or links) are greatly appreciated. Regards, Chris