One of the tasks that every Active Directory administrator has to learn is how to remove a failed or offline Domain Controller (DC) from the environment. The easiest method is to use DCPROMO, however if the DC is already offline or had a catastrophic failure this is not going to be an option. You also don't want to leave it to the Garbage Collection process as you will have nagging issues within Active Directory (AD). What you need to do is remove the DC's metadata info from AD. This involves using a command called NTDSUTIL. NTDSUTIL is a command line tool that allows you to perform some of the more advanced Active Directory maintenance tasks.
Below are the steps needed to remove a failed or offline Domain Controller from your environment. I have included additional steps that are needed to remove the leftover data in Active Directory Sites and Services as well as DNS. Those two areas are often overlooked.
TIP: NTDSUTIL does not require the full command to be entered; you only have to enter enough of the command that is unique. For Example, instead of typing
metadata cleanupyou could just type
met cleor better yet
Shouldn't Step 7:
Type select operations target
Type select operation target