If you have a situation where you may have just installed Windows XP or accidentally downloaded a corrupt .exe file allowing hackers to send messages to your screen through Windows Messenger Utility. This becomes very annoying as it can happen at any time no matter what program you are running. Also, the messenger utility isn’t that important unless you plan on sending messages over your network to others. To stop these messages, do as follows:

1) Open the Services window by going to “Start–>Run” and entering “services.msc”.
2) Double-click the “Messenger” entry in the list.
3) Click “Stop” to close the service.
4) Select “Disabled” from the “Startup type” list to prevent it from loading automatically the next time Windows starts.
5) Close the services window when you are done.