The domain join cannot be completed because the SID of the domain you attempted to join was identical to the SID of this ...

The domain join cannot be completed because the SID of the domain you attempted to join was identical to the SID of this machine. This is a symptom of an improperly cloned operating system install.  You should run sysprep on this machine in order to generate a new machine SID. Please see http://go.microsoft.com/fwlink/?LinkId=168895 for more information.