It's not MSN, it's part of the messenger and alerter services which are normally used to send messages to and from computers on a LAN. For example, the laser printers on the domain at my college will automatically send a message to the workstation that initiated the print job telling them the document is done printing when something gets printed. Home users dont' have much use for it. To shut it off so you don't get spammed, open the services control panel and stop the Alerter and Messenger services and set them to not auto start
