its not that it don't support tcp/ip (it does) it don't support RAS (Remote Access Service) this allows computers to make network connections to each other using telephone lines. a RAS connection running PPP can support the TCP/IP, IPX/SPX, and NetBEUI protocols simultaneously. you may browse a remote network and share files using NetBEUI, browse the internet using TCP/IP, and access a Novell netware file server using IPX--all over a single dial-up RAS connection.
hyperterminal is used, among other things, to send and receive text and data files to a remote computer. The status of the transfer is displayed in the Hyperterminal window during the transfer. you use your modem's AT commands to accomplish this. Hyperterminal is also used to configure certain devices through "console" and diagnos problems or set-up equiptment.
i hope that helps you understand it a little better. "Jack of all trades. Master of none."