Firefox users, if you're running the most recent release on Windows 7 you need to make a tiny tweak to your browser's configuration. It defeats the purpose of Aero's cool taskbar thumbnails feature if you have to open a window before you can scan which browser tabs you have open. IE8 shows all open tabs in thumbnail previews when you point to its icon. So how do you add the same feature to Firefox 3.6? I explain.
Source : Ed Bott's Microsoft Report