The correct way to do this is to install this freeware app
http://buzzdev.net/index.php?option=...5027#msg-15027
Run it and select the "Services" tab and set pmsnserver to disabled.
Just like disabling a service in Windows. Hotmail and MSN messenger or Live messenger will all be effected and will no longer work. If you have problems, just reset the service to "Automatic" Voila! Easy and no reg hacking.
-Paul