I had a DC and Exchange 2010 installed on the same machine. I removed the DC role, and Exchange server went crazy. I tried to install the DC role again to fix the problem but ran into this error when running DCPROMO: Active Directory Domain Services could not create the NTDS Settings object for this Active Directory Domain Controller CN=NTDS Settings,CN=DC1,CN=Servers,CN=Manukau,CN=Sites,CN=Configuration,DC=AccessGroupnz,DC=com on the remote AD DC Server1.AccessGroupnz.com. Ensure the provided network credentials have sufficient permissions. "The DSA operation is unable to proceed because of a DNS lookup failure." Do you think I need to run this in an elevated command prompt, or change credentials somewhere to domain admin? Or is it something else?