Win2008 DC in a Windows 2000 domain: can I keep the old DC?

Solution 1:

First make sure that all of your DCS have 2000 sp4, then raise the domain functional level to windows 2000 native. Also ensure that the forest functional level is 2000. After that you can add the 2008 domain controller (you will need to run adprep/forest prep etc). You can then transfer the roles to the new server, if you so desire. There is no need to move the operational roles at all unless they are all on one server. For guidance on role placement see Planning Operations Master Role Placement and FSMO placement and optimization on Active Directory domain controllers. You will not have issues with a mixed domain controller environment as long as you do not change the domain functional level.

However- you should verify that any applications are supported with 2008 domain controllers. Up until the beginning of february exchange 2003 was not supported with 2008 domain controllers (see this updated chart for current support)