Sending a message on LAN
First, turn on the messenger service on the PC you are sending the message from and the PC you are sending the message to.
Click on Start then run. Type in services.msc and press enter. Scroll down till you see Messenger. Right click Messenger > go to properties > start up type – automatic > apply > ok > Right click Messenger and select start.
Then to send message, click on Start then run and type in cmd and press enter. At the command prompt type in:
net send computername message and then press enter
where computername is the name of the computer you
want to send the message and message is the actual message.