Open Active Directory Users and Computers.

To open Active Directory Users and Computers, click Start, point to Administrative Tools, and then click Active Directory Users and Computers.

You can also open Active Directory Users and Computers from within Server Manager, by expanding Roles and then Active Directory Domain Services in the hierarchy pane, and then selecting Active Directory Users and Computers.

In the console tree, click the Computers folder.

In the details pane, right-click the computer you want to add to the domain, and then click Properties.

Click the UNIX Attributes tab.

In the NIS Domain list, select the domain to which you want to add the computer.

To save the changes and keep the dialog box open, click Apply. To save the changes and close the dialog box, click OK.