Guidelines for raising domain and forest functional levels

By | September 7, 2016

Guidelines for raising domain and forest functional levels

The following guidelines apply to raising the domain or forest functional levels:

  • You must be a member of the Domain Admins group to raise the domain functional level.
  • You must be a member of the Enterprise Admins group to raise the forest functional level.
  • You can raise the domain functional level on the primary domain controller (PDC) emulator operations master only. The AD DS administrative tools that you use to raise the domain functional level (the Active Directory Domains and Trusts snap-in and the Active Directory Users and Computers snap-in) automatically target the PDC emulator when you raise the domain functional level.
  • You can raise the forest functional level on the schema operations master only. Active Directory Domains and Trusts automatically targets the schema operations master when you raise the forest functional level.
  • You can raise the functional level of a domain only if all domain controllers in the domain run the version or versions of Windows Server that the new functional level supports.
  • You can raise the functional level of a forest only if all domain controllers in the forest run the version or versions of Windows Server that the new functional level supports.
  • You cannot set the domain functional level to a value that is lower than the forest functional level, but you can set it to a value that is equal to or higher than the forest functional level.
  • With versions of Windows Server that are earlier than Windows Server 2008 R2, you cannot roll back or lower a functional level under any circumstances. If you have to revert to a lower functional level with a version of Windows Server that is earlier than Windows Server 2008 R2, you must rebuild the domain or forest or restore it from a backup copy.
  • After you set the domain functional level, you cannot roll back or lower the domain functional level except in the cases listed in the following table. The domain functional level can be lowered only by using Windows PowerShell.

 

Current domain functional level

Current forest functional level

Rollback options

Windows Server 2012 R2 Windows Server 2012 R2 None unless you first lower forest functional level
Windows Server 2012 R2 Windows Server 2012 Windows Server 2012
Windows Server 2012 R2 Windows Server 2008 R2 Windows Server 2012 or Windows Server 2008 R2
Windows Server 2012 R2 Windows Server 2008 Windows Server 2012, Windows Server 2008 R2, or Windows Server 2008
Windows Server 2012 Windows Server 2012 None unless you first lower forest functional level
Windows Server 2012 Windows Server 2008 R2 Windows Server 2008 R2
Windows Server 2012 Windows Server 2008 Windows Server 2008 R2 or Windows Server 2008
Windows Server 2008 R2 Windows Server 2008 R2 None unless you first lower forest functional level
Windows Server 2008 R2 Windows Server 2008 Windows Server 2008
Windows Server 2008 or lower Windows Server 2008 or lower None
  • After you set the forest functional level, you cannot roll back or lower the forest functional level except in the cases listed in the following table. The forest functional level can be lowered only by using Windows PowerShell.

 

Current forest functional level Recycle Bin enabled? Rollback options
Windows Server 2012 R2 Yes Windows Server 2012 or Windows Server 2008 R2
Windows Server 2012 R2 No Windows Server 2012, Windows Server 2008, or Windows Server 2008 R2
Windows Server 2012 Yes Windows Server 2008 R2
Windows Server 2012 No Windows Server 2008 R2 or Windows Server 2008
Windows Server 2008 R2 Yes None
Windows Server 2008 R2 No Windows Server 2008