You can use the Windows Server 2008 domain rename process to change the names of your Active Directory domains, and you can also use it to change the structure of the domain trees in your Active Directory forest. This process involves updating the Domain Name System (DNS) and trust infrastructures as well as Group Policy and Service Principal Names (SPNs).
The following conditions must be in effect before you can begin a domain rename operation:
Note the following:
This task provides information about performing the domain rename operation. This task describes in detail the procedures that you complete to perform the domain rename operation in your forest. Be sure that you have reviewed and completed every preliminary procedure that applies to your domain rename conditions, as described in Preparing for the Domain Rename Operation.
After you complete all the procedures in this task, the target domain name changes will be effective in your forest. The domain name changes will have propagated toall the domain controllers in your forest, as well as to the member computers in the renamed domains.
A brief period of interruption in your Active Directory forest service occurs during the time when all of the domain controllers in the forest are automatically restarting. The exact point at which the service interruption occurs is indicated in Run Domain Rename Instructions. Except for this brief period of interruption, the Active Directory Domain Services (AD DS) service should continue to be available and function normally throughout the rest of the domain rename process.
The following is required to perform the procedures for this task:
To complete this task, perform the following procedures:
This article was sourced from the thread Can you rename Windows 2008 Domain on TechNet Windows Directory Services forum and includes information from the TechNet Library.