When you install Windows Live Messenger on your Windows 7 system, Microsoft starts running it whenever you’re logged in to the computer, which can be very annoying. To stop Windows 7 from automatically turning on Windows Live Messenger every time you're nearby, you need to modify Messenger’s options so that you have more control over the process.
To turn Messenger off, you need to first log off, then close the Messenger window. Log off by clicking the down arrow to the right of the Show Menu icon (to the right of the doughboy) and choose File→Sign Out. Then X out of Messenger window.
There are several different ways to tell Windows 7 not to start Windows Live Messenger every time Windows starts, but the easiest way is through the Messenger options panel:
If you aren’t signed in to Windows Live Messenger, use your Windows Live ID and sign in.
You can use any valid Windows Live ID.
Click the down arrow to the right of the Show Menus icon (which is to the right of the doughboy with the plus sign) and choose Tools→Options. Click Sign In on the left.
You see the sign-in options.
Deselect the check box marked Automatically Run Windows Live Messenger When I Log On to Windows.
You might also want to deselect a couple of other annoying Messenger habits.
To keep Windows Live Messenger from showing the Windows Live Today screen, deselect the check box marked Show Windows Live Today after I Sign In to Messenger.
To keep Messenger from turning on every time you go online, deselect the Allow Automatic Sign In When Connected to the Internet check box.
Click OK.
Restart Windows just to make sure that you’ve driven a wooden stake through Windows Live Messenger’s autostarting heart.
Windows Live Messenger is a free add-on for Windows 7. To obtain Windows Live Messenger, you need to visit Windows Live and download the latest version.