NETBIOS is required in order for pc's to be able to share resources, even in win2k3. Usually it is enabled in TCP/IP by default, but in some cases it is not. It does however, open up a large security hole that even microsoft has not even considered. Anyone with knowledge of the netuse command and a good password cracker can access a pc on the internet that has NETBIOS enabled. Personally, i think NETBIOS is a horrid idea for this reason, but unfortunately pc's cannot share resources on a windows-based network without it