I’ve heard mixed feelings about the new Windows Live Messenger behavior when running on Windows 7; specifically, how the application stays docked in the Taskbar while running in the background.

The nice thing about the application always being in the new taskbar is the ability to more quickly interact with commonly used features. A Windows 7 jump list gives you fast access to common tasks for the application, such as changing your presence, accessing your Windows Live mail, etc. This is great if you’re a frequent user of the application.
However, if you’re like me and are not a frequent user of the application, having Windows Live Messenger always on your Taskbar even though you didn’t choose to pin it there, is a bit of an annoyance. You might prefer the previous behavior where the application runs quietly in the background within the notification area until an event comes in; or if you choose to open the application. To do this, navigate to where you installed Windows Live Messenger (usually %ProgramFiles%\Windows Live\Messenger\), right-click on msnmsgr.exe and choose properties. From the Compatibility tab, specify the application should run in compatibility mode for Windows Vista.
Voila! Windows Live Messenger is tucked nicely away in the fly-out list for applications running in the notification area. Events happen the same way whether you run the application in compatibility mode, or in the default mode as part of the Taskbar. Even better, when you decide to use the application, the great new experience is revealed (the icon is displayed in the Taskbar; light-up notifications, jump list and all).

