To access the Active Directory Schema a DLL needs to be manually registered to allow access.

Its hidden away to stop admins that dont know what they are doing from playing with potentially dangerous tools. Use this with caution. Very handy when you know what your doing.

This registers the dynamic link library (DLL) for the Active Directory Schema and only needs to be done once on a computer.

Register the Active Directory Schema snap-in

regsvr32.exe schmmgmt.dll