The messenger service is useful on company networks where there is a network adminisrator who may need to send messages to everyone on the network but it serves no purpose on a home network which doesn't have a network administrator. In fact the only purpose that the messenger service (which is NOT Windows Messenger) serves on a home network is to provide yet another security hole for you to receive spam (and perhaps worse). For a home network you really want this service turned off.
To do this go into the Control Panel and select Services. Scroll down to find the Messenger service and then press the Stop button and then Yes. That turns the service off for now. To stop it coming on again next time you boot the computer you need to then press the Startup button and change the option from Automatic to Disabled. You will need to have administrator access in order to perform this more permanent update.
This article written by Stephen Chapman, Felgall Pty Ltd.