Raise the forest functional level

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

To raise the forest functional level

Open Active Directory Domains and Trusts.
In the console tree, right-click the Active Directory Domains and Trusts node, and then click Raise Forest Functional Level.
In Select an available forest functional level, click Windows Server 2003, and then click Raise.

Caution

If you have or will have any domain controllers running Windows NT 4.0 and earlier or Windows 2000, then do not raise the forest functional level to Windows Server 2003. Once the forest functional level has been set to Windows Server 2003, it cannot be changed back to Windows 2000.

Notes

To perform this procedure, you must be a member of the Domain Admins group (in the forest root domain) or the Enterprise Admins group in Active Directory, or you must have been delegated the appropriate authority. As a security best practice, consider using Run as to perform this procedure. For more information, see Default local groups, Default groups, and Using Run as.
To open Active Directory Domains and Trusts, click Start, click Control Panel, double-click Administrative Tools, and then double-click Active Directory Domains and Trusts.
Windows 2000 native is the minimum domain functionality requirement for raising the forest functional level to Windows Server 2003.
To raise the forest functional level, you must first upgrade (or demote) all existing Windows 2000 domain controllers within your forest.
If you are unable to raise the forest functional level, you can click Save As in the Raise Forest Functional Level dialog box to save a log file that specifies which domain controllers in the forest still need to be upgraded from Windows NT or Windows 2000.
The current forest functional level is displayed under Current forest functional level in the Raise Forest Functional Level dialog box.

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