Demoting the domain controller is only the first step in replacing the domain controller. Although the domain controller has been demoted, the server still exists as a domain member (a member server). Therefore, the next step in the process is to remove the server from the domain.

What happens when you demote a domain controller?

It is important to demote a server before decommissioning or rebuilding it so that its associated objects in Active Directory are removed, its DNS locator resource records are dynamically removed, and replication with the other domain controllers is not interrupted.

Does demoting a DC remove it from the domain?

Clear the Active Directory Domain Services check box to demote a domain controller; if the server is currently a domain controller, this does not remove the AD DS role and instead switches to a Validation Results dialog with the offer to demote. Otherwise, it removes the binaries like any other role feature.