I actually am having this problem now, there is no 4th option as that was the one I was originally looking for. I didn't remove messenger, instead I renamed it MessengerOff, but that was after the problem began occuring.
What is the EXACT registery to totally stop it? The one you put has a big ass space in it, I dunno if it's missing anything, and it doesn't work when I filled it in, Tell me exactly where to go, what to create, etc please.