Raise the Functional Levels of Domains and Forests

  • Article

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

To enable all Windows Server 2003 Active Directory features, raise the functional level of your forest to Windows Server 2003. This will automatically raise the functional level of all domains to Windows Server 2003.

Important

  • Raising the domain and forest functional levels to Windows Server 2003 is a nonreversible task and prohibits the addition of Windows NT 4.0–based or Windows 2000–based domain controllers to the environment. Any existing Windows NT 4.0 or Windows 2000–based domain controllers in the environment will no longer function. Before raising functional levels to take advantage of advanced Windows Server 2003 features, ensure that you will never need to install domain controllers running Windows NT 4.0 or Windows 2000 in your environment.

After all domains are operating at the Windows Server 2003 functional level, raise the forest functional level to Windows Server 2003. To do this, right-click Active Directory Domains and Trusts in Active Directory Domains and Trusts, and select Raise Forest Functional Level. This allows you to take advantage of all Windows Server 2003 forest-level features.

Note

  • You can only raise the functional level of the forest to Windows Server 2003 if all domains are set to the Windows 2000 native functional level or higher.

For more information about enabling functional levels after upgrading from a Windows 2000 environment and the features available at the Windows Server 2003 domain and forest functional levels, see "Enabling Advanced Windows Server 2003 Active Directory Features" in this book.