A free no frills chat client built into Xp.

WinChat For XP is a simple peer-to-peer chatting program. You can use Chat on your computer to communicate with someone on another computer. Both computers must be connected to the same network; for example, a LAN or the Internet. Also, each computer must be running a similar protocol, such as TCP/IP. Your friend also needs to have winchat running to dial into him/her.

Chat is interactive. You see a reply to your messages as the other person types it.

The Chat window is separated into two panes: one contains the messages you send, and the other contains the messages you receive.

To use Windows XP built in Chat ....

Go to Start --> Run and type winchat

Thanks to xp-erience.org for this!
enjoy,
BB