Cannot find DNS hostname for server :computer name.
This message indicates that there is a communications problem with Active Directory, the server hosting Active Directory is down, the server name was mistyped, or the server you tried to contact is not part of Active Directory.
To correct this problem: 1) Open Event Viewer and check for events indicating a problem with Active Directory or the network, 2) Check the server to see if it is down, 3) Retry the command, or 4) Check to see if the server is in Active Directory.