I have ( I think ) Windows Messenger, or .Net Messenger

I can't find it to turn it off.
I use MSN Messenger 7 without any problems, and have that set up to NOT fire up on auto when I connect to the net. But sometimes people say "Hello" if I'm connected to the net; in a window/box that looks like an old version of msn - beforeI fire up msn. If I then fire up MSN, the previous boxes close with a message along the lines of "You've been logged out there because you've logged in somewhere else"
I've clicked the "help", "about" thingy, and that tells me it's version of Windows Messenger. In the WM box, there is no "tools" menu drop down, so I can't go there to turn it off.
I understand that WM is part of (?) XP Home Edition, but can't find it in the programmes lists, or anywhere else.
PMSL - All that ^^^^^ to say "Can anyone help me turn off Windows Messenger without affecting MSN 7 ??"
If this is locked - please - please somebody, anybody, everybody (not) PM an answer or call/text/email/write it on the side of a cow
