How to change your default desktop session

• Method 1:
  • edit /etc/lightdm/lightdm.conf, change user-session to the session you want.
    To list the available session names:
    • cat /usr/share/xsessions/* | grep 'session=' | awk '{print $2}' | sed "s/--session=//g"
• Method 2:
  • Set gnome-shell as default:

    sudo apt-get install gnome-shell
    sudo /usr/lib/lightdm/lightdm-set-defaults -s gnome-shell
    

  • Set gnome classic as default:

    sudo apt-get install gnome-session-fallback
    sudo /usr/lib/lightdm/lightdm-set-defaults -s gnome-classic
    

  • Set unity as default:

    sudo /usr/lib/lightdm/lightdm-set-defaults -s ubuntu
    

See also

• http://askubuntu.com/questions/62833/how-do-i-change-the-default-session-for-when-using-auto-logins
• http://www.addictivetips.com/ubuntu-linux-tips/how-to-auto-login-to-gnome-in-ubuntu-11-10-tip/