If you want a private chat with a friend or client on you Network, you don't need to download any fancy program! All you need is your friends IP address and Command Prompt. Firstly, open Notepad and enter:
@echo off :A Cls echo MESSENGER set /p n=User: set /p m=Message: net send %n% %m% Pause Goto A
Now save this as "Messenger.bat". Open the .bat file and in Command Prompt you should see:
MESSENGER User:
After "User" type the IP address of the computer you want to contact. After this, you should see this: Message: Now type in the message you wish to send. Before you press "Enter" it should look like this:
MESSENGER User: 56.108.104.107 Message: Hi
Now all you need to do is press "Enter", and start chatting!