Item Details

Forest name

Specifies the name of the selected forest.

Current forest functional level

Specifies the current setting of the forest functional level.

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

The functional level of a domain or forest only defines the set of Windows operating systems that can run on domain controllers. It does not define the client operating systems that are supported in the forest.

Additional references