Q. I'm using Ntdsutil in Windows Server 2008, but I'm receiving errors saying that an instance isn't selected.
A. In Windows 2008, there can be many directory service instances on one box, be they Active Directory (AD) NTDS instances or lightweight directory service instances. Prior to running commands in Ntdsutil that affect AD, you should select the AD instance via the activate command, as the following example shows:
activate instance ntdsThe other commands should then work normally.