CMD Message sending (Net send)
CMD Message sending (Net send)
The purpose of using the net send command is to send a message to a computer on your network or to send a message to a entire domain.
Note: this message service was disable on Windows XP SP2 and later versions, it can be re-enabled in services. Starting or stopping Windows Services
At the CMD prompt: c:\>net send (computer name or domain) (message) see screenshot below (fig.1).

fig.1 Using the net send command.
The result is the a small box with your message on the computer(s) you have sent to (fig.2)

fi.2 A net send message sent to the whole domain or workgroup.