If you are deploying a multiserver installation, all machines must be members of an Active Directory domain. When using machines that are members of an Active Directory domain, the Team Foundation Server requires that the domain not contain Windows NT 4.0 domain controllers.
For a Windows 2000 Active Directory domain, only native mode controllers are permitted. Mixed mode controllers are prohibited. If you attempt to use mixed mode controllers, the base Web services used by Team Foundation Server can't connect to the data tier. Everything may seem to install correctly, but you'll begin to receive really strange errors when using Team Explorer.
For a Windows 2003 Active Directory domain, only the standard mode controllers are permitted. Interim mode controllers are prohibited.