The net send command is a useful Windows command to post a quick message to any PC connected to your LAN. However, since it is invoked via the command line, it is not very convenient. Here is a simple AutoHotKey script to wrap a GUI around the net send command.

First, if you haven’t done so already, install AutoHotKey. Then type out this command in file netsend.ahk and double click to execute.

^!N::
  inputbox, msg, Message,,,300,100
  Run, cmd.exe "/c net send 192.168.0.1 %msg%"
return

To keep things simple, the script directly contains the IP address (or hostname) of the computer you want to contact; if you want to message multiple people, you might have to add an IP field to the GUI and make necessary changes to the script.

netsend

To invoke the prompt, press Ctrl + Alt + N, enter the message, then press the OK button, and the message is instantly delivered to the recipient.