Ruben Laguna’s blog

How to Enable Windows Key as Super Key in Linux

I’ve you tried beryl or compiz you probably had notice that the Super key (the windows key, also known as Meta key) is used a lot. By default in my Fedora Core 6 installation the Windows key is not enabled, I had to add Option "XkbOptions" "altwin:super_win" to the InputDevice section of my /etc/X11/xorg.conf to activate it.

This is how the InputDevice section look like now:

Section "InputDevice"
        Identifier  "Keyboard0"
        Driver      "kbd"
        Option      "XkbModel" "pc105"
        Option      "XkbLayout" "es"
        Option      "XkbOptions" "altwin:super_win"

via Noiesmo’s GNU/Linux Site