Messenger Service not working

I enabled "Messenger Service" ( automatic startup ) to be able to use the "net send"
command.
However, when I reboot my computer, despite the fact that Messenger is reported as
"started", when I issue the "net send" command I get an error message. I have to manually
stop and start again the service to be able to communicate with the networked computers
( wireless home network, Windows XP ).
Can somebody please help ?
Thanks.

Mike

Mike