With Windows 8 and Windows Server 2012, we also introduced something better.
It is called Active Directory-Based Activation.
It only works with Windows 8, Windows Server 2012, and later and it is forest wide. So for Windows 7/2008 R2 and earlier, you’ll still need to maintain those old KMS hosts.
You do not need to have your forest and functional levels at 2012, but you must have updated the schema to support these operating systems using ADPREP. ADPREP is still located on the Windows media if you plan on running it from one of the existing DCs in the environment.
1) If you haven’t already done so, run ADPREP from the Windows Server 2012 media to update the schema to support Active Directory-Based Activation.