Raise Your Domain and Forest Functional Levels

  • Article

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

Although the Windows Server 2003 domain functional level provides a number of features and advantages, enable this functional level only when all your Windows NT 4.0 BDCs have been upgraded and you are certain that your environment is ready.

Important

  • If you raise the domain and forest functional levels to Windows Server 2003, this action cannot be reversed and you cannot add 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 you raise functional levels to take advantage of advanced Windows Server 2003 features, ensure that you will never need to install domain controllers that run Windows NT 4.0 or Windows 2000 in your environment.

After you determine that your environment is ready, use Active Directory Domains and Trusts to enable the Windows Server 2003 domain functional level.

After all domains are operating at the Windows Server 2003 functional level, raise the forest functional level to Windows Server 2003 to take advantage of all Windows Server 2003 forest-level features.

For more information about enabling functional levels 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.