I installed one AD when Microsoft Windows Server 2012 was still in Release Candidate with the Datacenter edition, of course since few days my DC was rebooting every hour, the trial licence did expire few days ago.. So I had to install a new DC and promote it the transfer all FSMO roles from my “old” server to the new one.
First thing I had to do is to add this new server to the existing forest as a new domain controller :