Microsoft Knowledge Base Article 323357 contains the following summary:
This step-by-step article describes how to configure a
running Windows Server 2003 with TCP/IP networking while NetBIOS is
On a computer running Windows Server 2003, you can turn off NetBIOS over TCP/IP (NetBT) for selected clients on an "as needed" basis. If you prefer to only use DNS to provide name registration and resolution on a specified computer that is used in a specialized or secured role for your network, you can turn off NetBT services for one or all of the network adapters that are installed on that computer.