Question : Demoting a PDC to a BDC

The menu item in Server Manager under the Computer Menu stating "Promote to Primary Domain Controller" is gray, and there isn't an option to Demote to BDC, even though this computer is BDC.
Is it a permissions issue?

Answer : Demoting a PDC to a BDC

For the "Promote to PDC" menu item to be available, you must be logged in as a domain administrator and you must have selected a BDC from the list of servers in server manager.

Demote to BDC is only available in the _very rare_ circumstance that:
1. The PDC goes off-line.
2. You promote a BDC to take it's place.
3. You plug in the original PDC and now have two PDCs.
4. You must select one of the PDCs and demote it because 2 PDCs cannot be online at the same time.