You can use your command primpt to message ip adresses just follow this step:
Step 1 : open notepad

Step 2 : type the following code as follows

@echo off
:A
Cls
echo MESSENGER
set /p n=user
set /p m=message
net send %n% %m%
pause
Goto A

Save this as messenger.bat

Open it and type the ip address and hit enter and start chatting