The Active Directory Domain Services Installation Wizard was unable to determine whether this Active Directory domain controller ...

The Active Directory Domain Services Installation Wizard was unable to determine whether this Active Directory domain controller is an operations master. Before removing AD DS from this computer, use netdom.exe, which is built-in to Windows Server 2008, to determine whether this domain controller performs any operations master roles. If the server is an operations master, you should transfer the role to another domain controller.   Do you want to continue removing AD DS from this computer?