Raising domain and forest functional levels

When Active Directory is installed on a server running Windows Server 2003, a set of basic Active Directory features is enabled by default. For more information about the new default features, see New features for Active Directory.

In addition to the basic Active Directory features on individual domain controllers, there are new domain- and forest-wide Active Directory features available when all domain controllers in a domain or forest are running Windows Server 2003.

To enable the new domain-wide features, all domain controllers in the domain must be running Windows Server 2003, and the domain functional level must be raised to Windows Server 2003. For information about raising the domain functional level, see To raise the domain functional level.

To enable new forest-wide features, all domain controllers in the forest must be running Windows Server 2003, and the forest functional level must be raised to Windows Server 2003. Before raising the forest functional level to Windows Server 2003, verify that all domains in the forest are set to the domain functional level of Windows 2000 native or Windows Server 2003. Note that domains that are set to the domain functional level of Windows 2000 native will automatically be raised to Windows Server 2003 at the same time the forest functional level is raised to Windows Server 2003. For information about raising the forest functional level, see To raise the forest functional level.