When you install Active Directory Domain Services (AD DS) on a server running Windows Server 2008 R2, a set of basic Active Directory features is enabled by default. In addition to the basic Active Directory features on individual domain controllers, there are new domain-wide and forest-wide Active Directory features that are available when all domain controllers in a domain or forest are running Windows Server 2008 R2. For more information, see Understanding Domain and Forest Functionality.

For the new domain-wide features to be enabled, all domain controllers in the domain must be running Windows Server 2008 R2, and the domain functional level must be raised to Windows Server 2008 R2. You can use the following procedure to raise the domain functional level using Active Directory Administrative Center.

Membership in Domain Admins in the domain for which you want to raise the functional level or Enterprise Admins in AD DS, or equivalent, is the minimum required to complete this procedure. Review details about using the appropriate accounts and group memberships at http://go.microsoft.com/fwlink/?LinkId=83477.

To raise the domain functional level using Active Directory Administrative Center
  1. To open Active Directory Administrative Center, click Start, click Administrative Tools, and then click Active Directory Administrative Center.

    Note

    Another way to open Active Directory Administrative Center is to click Start, click Run, and then type dsac.exe.

  2. In the navigation pane, right-click the domain for which you want to raise the functional level, and then click Raise the domain functional level.

  3. In Select an available domain functional level, do one of the following:

    • To raise the domain functional level to Windows Server 2008, click Windows Server 2008, and then click OK.

    • To raise the domain functional level to Windows Server 2008 R2, click Windows Server 2008 R2, and then click OK.

Caution
  • After you set the domain functional level to a certain value, you cannot roll back or lower the domain functional level, with one exception: when you raise the domain functional level to Windows Server 2008 R2 and if the forest functional level is Windows Server 2008 or lower, you have the option of rolling the domain functional level back to Windows Server 2008.
  • You can lower the domain functional level only from Windows Server 2008 R2 to Windows Server 2008. If the domain functional level is set to Windows Server 2008 R2, it cannot be rolled back, for example, to Windows Server 2003.

Additional considerations

  • You can also perform the task in this procedure by using the Active Directory module for Windows PowerShell. To open the Active Directory module, click Start, click Administrative Tools, and then click Active Directory Module for Windows PowerShell. For more information, see Raise the Domain Functional Level (http://go.microsoft.com/fwlink/?LinkId=141909).

    For more information about Windows PowerShell, see Windows PowerShell (http://go.microsoft.com/fwlink/?LinkID=102372).

Additional references