Add a Domain
Applies To: Windows Server 2008
After performing this procedure, you can view and manage an existing Active Directory domain using Group Policy Management Console (GPMC).
To add a domain in GPMC
In the GPMC console tree, double-click the forest to which you want to add a domain, right-click Domains, and then click Show Domains.
In the Show Domains dialog box, select the check box next to each domain to be added to GPMC, and then click OK.
Additional considerations
Adding a domain to GPMC does not actually create a new domain in Active Directory.
Domains are always shown as peers of each other, regardless of their actual relationship.
You can use the Add Forest function to add externally trusted domains.