Here's the sledge hammer approach to fixing it
Go to start-->settings-->control panel-->computer management-->services
Find "messenger" in the list. Right click, and stop it. Answer yes to the nag messages. Now, right click again on it, and do properties. In the "startup" drop down, choose disabled. Close hit "ok" at the bottom, and close the services window.
Should be fixed.
It's kind of a brute force way of stopping it, but it works. I've done it on some of my machines, and haven't noticed any negative results because of it.