In a Windows .NET domain, you may rename a domain controller (i.e., change its FQDN and NetBIOS names). To rename a domain controller from the local console:
Open the System Properties window. (Press the <Win>+<Pause/Break> keys, or click System in Control Panel.)
On the Computer Name tab, click Change.
Click OK to continue renaming.
Enter a new computer name and click OK.
Enter a domain administrator's credentials if required.
Restart the domain controller. Wait until the DNS information and Active Directory replication topology is renewed. After that, the clients and replication partners will be able to locate the renamed DC and be authenticated on it. Verify the DC with the dcdiag and repadmin /showreps commands.
To rename domain controllers, you must first raise the domain functional level to Windows .NET. This is because only Windows .NET-based domain controllers support the msDS-AdditionalDnsHostName, msDS-AdditionalSamAccountName, and some other attributes necessary to perform renaming. This means that it is not possible to rename a DC in a Windows 2000 domain.
The rename operation does not change the domain membership of the controller, i.e., it does not allow you to move a DC to another domain (even if you change the primary DNS suffix). To do so, you must first demote the DC and promote it with a new domain name.
To rename a remote domain controller, it is necessary to use the NetDom.exe utility. The renaming procedure is not complicated and is described in the Help and Support Center (search for the "rename controller" words).