Unsupported Domain Configurations
Domain configurations that support the functional modes of Windows NT Server 4.0 are unsupported. Some specific examples of unsupported Team Foundation Server domain configurations are as follows:
Windows 2000 mixed mode domains are not supported.
Windows Server 2003 domain controllers configured as Windows 2000 mixed-mode functional level are not supported.
Configuring the application tier and data tier between a domain and a workgroup.