This article describes how to remove data in Active Directory after an unsuccessful domain controller demotion.
Warning If you use the ADSI Edit snap-in, the LDP utility, or any other LDAP version 3 client, and you incorrectly modify the attributes of Active Directory objects, you can cause serious problems. These problems may require you to reinstall Microsoft Windows 2000 Server, Microsoft Windows Server 2003, Microsoft Exchange 2000 Server, Microsoft Exchange Server 2003, or both Windows and Exchange. Microsoft cannot guarantee that problems that occur if you incorrectly modify Active Directory object attributes can be solved. Modify these attributes at your own risk.
The Active Directory Installation Wizard (Dcpromo.exe) is used for promoting a server to a domain controller and for demoting a domain controller to a member server (or to a stand-alone server in a workgroup if the domain controller is the last in the domain). As part of the demotion process, the wizard removes the configuration data for the domain controller from Active Directory. This data takes the form of an NTDS Settings object that exists as a child of the server object in Active Directory Sites and Services.