FAQ: Q40
Link: http://www.ilopia.com/FAQ/FAQ.aspx?id=40
Can I install Exchange 2000 on a machine running Windows Server 2003?
No, you cannot install Exchange 2000
(regardless of Service Pack) on a Windows Server 2003 machine. You can however
run Exchange 2000 (with SP3 or above) on a Domain Controller running Windows
2000 (with SP3 or above) that is part of a Windows Server 2003 Domain. Exchange
2003 will be the first version of Exchange that will install and run on Windows
Server 2003. You can find more information about Exchange 2003 and download a
trial version here