I have to be a little skeptical about Microsoft's claims. I was one of those active users in that I'd registered my hotmail account when I installed Windows 7, and Messenger came along for the ride - as with tens if not hundreds of millions of others - however it had long been replaced with other services.
Not least because it became more and more obnoxious. It was a very self-important little IM.
I wasn't being sarcastic. I was legitimately asking what the scenario is that would have you logging into Messenger on a regular basis while never using it.
I'm still not clear what scenario has you logging into Messenger automatically on Windows 7. Were/are you running the Messenger client? I'm not aware of any Win7 SKU that shipped with Messenger. That's part of Windows [Live] Essentials. Maybe some OEMs shipped with this preinstalled? I don't recall Windows 7 by itself ever asking me to provide it with my LiveId/Microsoft Account.
Not least because it became more and more obnoxious. It was a very self-important little IM.