gnome 3.4 - disable Alt windows dragging

This behavior is very annoying. So I spent ~30 minutes to find working solution.
I tested on Fedora 17, it works!

Install dconf-editor:
sudo yum install dconf-editor

Then run:
dconf-editor

Then navigate to:
org → gnome → desktop → wm → preferences → mouse-button-modifier

Change the value to:<Super>
or:<Super><Alt>


Close the dconf-editor window.