heres a lil more info
Well let me give you a lil more info..
When I was in school Im almost sertain we were on Win-2000 with regular user rights not admin rights and I have no clue as to what the very simple and short code was but I do think it had name of the computer you were trying to message in the code.
basically you can message any computer on the local network it might have been a windows ALERT and not a message but not sure about this.
Im currently on a network managed by WinServer 2003 and our systems are running on Win98..
Hope this info helps.