Gussery is correct.
You may, however, set up a peer-to-peer Local Area Network (LAN) with one Windows XP acting as a Dynamic Host Configuration Protocol (DHCP) server. The other computers in your LAN will then be able to share a connection to the Internet through this server (as long as they have Windows 98 SE or a later version of Windows installed). The nodes on your LAN would have to be connected through an inexpensive hub, network interface cards (NICs), and CAT 5 or 6 cables.
Regards,
Doc