You need to run dcpromo and tell it to make a secondary domain controller in an existing domain. Once it's all done it will reboot the machine and then you can use your domain login.

In our Active Directory domain, we’d like to manage users and groups from a workstation rather than from the server. How can I get the Active Directory Users and Computers application into my XP ...

If the Server is not operational message keeps troubling you when adding a trusted domain user to a trusted domain in Windows Server, then this post may help you resolve the issue. When you click ...