Can I run Microsoft Exchange 2000 Server on Windows Server 2003?
In a word, no. The Microsoft article "XADM: You Cannot Install Exchange 2000 on a Computer That Is Running Windows Server 2003" (http://
support.microsoft.com/?kbid=321648) states that you can run Exchange 2000 only on a Windows 2000 server. However, Exchange 2000 Service Pack 3 (SP3) and later can run in mixed Windows 2003 and Win2K environments with Windows 2003 domain controllers (DCs).
—Paul Robichaux