Why can't I join a Windows NT 4.0 domain from a Windows XP or Windows 2000 client?

A. XP and Win2K use DNS instead of NetBIOS to name domains. As a result, if you've installed only TCP/IP on the XP or Win2K client and you've disabled NetBIOS over TCP/IP, the client can't join an NT 4.0 domain. To enable NetBIOS over TCP/IP, perform the following steps:

1. From the Start menu, select Settings, and click Network and Dial-up Connection.
2. Right-click Local Area Connection, and select Properties from the context menu.
3. Click Internet Protocol (TCP/IP), and click Properties.
4. Click Advanced, and select the WINS tab.
5. Click "Enable NetBIOS over TCP/IP."
6. Click OK, and ignore the WINS error.
7. Click OK to close all dialog boxes.

If you don't want to use NetBIOS over TCP/IP, you can instead use NetBEUI on all clients.