Installing Active Directory Domain Services (AD-DS)
In Windows Server 2008, unlike previous server operating Systems, there is an additional step that needs to be taken before running DCPROMO to promote the server to Domain Controller and installing Active Directory on it. This step is the installation of Active Directory Domain Services (AD-DS) role on the server. In fact, the AD-DS role is what enables the server to act as a Domain Controller, but you will still need to run DCPROMO the regular way.
AD-DS can be installed in one of 3 methods:
Method 1 – Server Manager/ Initial Configuration Tasks
Roles can and should be added from Server Manager (but they can also be initiated from the Initial Configuration Tasks wizard that auto-opens the first time you log on to the server).
1. Open Server Manager by clicking the icon in the Quick Launch toolbar, or from the Administrative Tools folder.
2. Wait till it finishes loading, then click on Roles > Add Roles link.
