The Active Directory Domain Services Installation Wizard automatically removes associated metadata from the forest when it successfully removes Active Directory Domain Services (AD DS) from a domain controller. However, certain conditions, such as lack of network connectivity, may prevent the wizard from successfully removing AD DS. If you force the removal of AD DS because the wizard cannot run successfully on the domain controller, you must delete the domain controller object. If you perform the deletion on a domain controller that runs Windows Server 2008 or Windows Server 2008 R2, the metadata that is associated with the deleted domain controller is cleaned up automatically. This eliminates the need to perform metadata cleanup, as is required for domain controllers that run Windows 2000 Server or Windows Server 2003.
To delete the domain controller object, open the Active Directory Users and Computers snap-in or the Active Directory Sites and Services snap-in, navigate to the domain controller object that you want to delete, right-click it, and then click Delete.
For more information, see AD DS Installation and Removal Step-by-Step Guide (http://go.microsoft.com/fwlink/?LinkID=139657).