In this tutorial, we will help you enable the ALT-TAB feature in Gnome Classic for Ubuntu 12.10/12.04. This feature is disabled by default under Gnome Classic and can be easily enabled via CCSM (CompizConfig Settings Manager).
1. Installing and Accessing Gnome Classic
If you haven't already installed GNOME Classic, you can do with this command under Ubuntu 12.10/12.04:
sudo apt-get install gnome-shell
Log out now the current session and select "GNOME Classic" from the session menu and log back in:
2. Enabling The ALT-TAB Behavior
Install first CCSM with this command from the terminal:
sudo apt-get install compizconfig-settings-manager compiz-plugins
Start now CCSM with this command:
In the left pane of the window, click Window Management, then in the right side of the window, check on "Application Switcher":
You have now enabled the ALT-TAB behavior!