1. How many Nics are in the machine?
2. Is the machine a DC?
3. Does the machine run DNS on it?
Make sure the DNS settings on the machine point to the right Active
Directory DNS Server. If the machine itself is the AD DNS Server point the
DNS settings on the NIC to 127.0.0.1
If there is more than one Nic make sure the NIC associated with the proper
subnet and with the right DNS settings is set to the higher prioity in the
Properties of Net'Hood, Advanced --> Advanced Settings..."
Sometimes to get the machine to boot up so you can get to these settings to
change them, you can get it to boot by starting it up with the network
cables unpluged, then plug them in after it is at the Crtl-Alt-Del prompt.