When a domain controller server is crashed and it still exists in an active directory setup, then it can make trouble later when you are promoting new machines to the domain controller.
This guide is written to help you clean up your active directory setup.
1. At the command prompt, type in the following commands:
C:\WINDOWS>ntdsutil ntdsutil: metadata cleanup metadata cleanup: connections server connections: connect to server <your domain controller name which you want to clean up> server connections: quit metadata cleanup: select operation target select operation target: list domains select operation target: select domain <number corresponding to the domain in which the failed domain controller was located> select operation target: list sites select operation target: select site <number corresponding to the site where failed domain controller is located> select operation target: list servers in site select operation target: select server <number which refers to domain controller to be removed> select operation target: quit metadata cleanup: remove selected server
When you receive an error message, click Yes. You are done with removing your failed domain controllers.
Type quit until you exit from the command prompt.
2. Open active directory sites and services, remove the object associated with failed domain controller.
3. Open active directory users and computers and go to the domain controller folder, delete the object associated with failed domain controller.
4. Open DNS console and delete the object associated with the failed domain controller including CNAME HOSTNAME and other DNS records.