There are 2 ways to get rid of Windows Messenger, either by disabling it or by uninstalling it. For those who want to keep things intact but just toggle the on/off switch, here is how you can disable Windows Messenger:
Click the [Start] button, then [Run], type in “services.msc” and press [Enter]. Look for the Messenger in the list, right click on it and toggle the Startup type to “Disable”. Alternatively, if you want to stop the service only without disable it for good until the next restart, you can do this by pressing Stop.
If you want to uninstall Windows Messenger, press the [Start] button, once again click on [Run] and copy/paste the following command “RunDll32 advpack.dll,LaunchINFSection %windir%\INF\msmsgs.inf,BLC.Remove” and press [Ok]. You can restart your computer now to see the changes.