TechNet had duplicated content about Active Directory functional levels. The duplication caused inconsistencies as one location got updated but not the other. So the duplication has been eliminated, but I am told it has made it harder to find for some of you who searching for this information. So to improve the discoverability of this information, I am posting this reminder that a complete list of Active Directory domain and forest functional levels and the features that are available at each level is published at:
There is also information about how Active Directory functional levels work at
Any feedback on these topics is appreciated.
Active Directory Documentation Team
This posting is provided "AS IS" with no warranties, and confers no rights.