I am in the process of migrating our domain from Windows 2000 domain controllers to Windows 2008 domain controllers. As it stands now there are 2 Windows 2000 dcs and 1 Windows 2008 dc. Is it the correct process to get to the functional level of Windows 2008 to install another Windows 2008 server, make it a DC, and then Raise the Domain Functional Level on one of the Win2008 DCs? At this point would I need to do anything to the old Win 2000 dcs or are they rendered out of service when I raise the functional level? I need our domain to be at Windows 2008 for several apps including Exchange 2010. Guidance on the correct steps and order will be appreciated.