When you right-click on My Computer / Properties / Network Identification / Properties and try to join a Windows NT domain, you receive:
The specified domain either does not exist or could not be contacted.</b>
The network path was not found.</b>
If your only protocol is TCP/IP and you disabled NetBIOS over TCP/IP, that is probably your problem.
This can also be caused by some 3rd party DNS servers, that do not support SRV records.
To enable NetBIOS over TCP/IP:
1. Start / Settings / Network and Dial-up Connections.
2. Right-click Local Area Connection and press Properties.
3. Select Internet Protocol (TCP/IP) and press Properties / Adsvanced / Wins.
4. Click Enable NetBIOS over TCP/IP.
5. Press OK until you are out. You can ignore the 'empty primary WINS address' message.
If you don't want to enable NetBIOS over TCP/IP, you could install NetBEUI on the clients and the server.