hi i'm using cmd to send messages accross a network but i have problems i type "msg xxx.xxx.xxx" than it asks for the message but when i send it, it doesn't pop up on the other computers screen how would i do this thanks

I'm not familiar with 'msg' but you can type:

net send pc_name_here "Your message goes here"

The 'Messenger' service must be running on the target machine for it to work, which it is by default.

This is one of the services that may be firewalled, too, as it's had some security problems in the past.