Fix random freezes Ubuntu 12.04

• Machine : HP DV7
  OS : Ubuntu 12.04
  Kernel : 3.5.0-41-generic
  Time : 5 minutes

  [0/3] Fix random freezes in Ubuntu 12.04

• sudo vi /etc/lightdm/lightdm.conf

  [1/3] Open a terminal and type

• user-session=ubuntu-2d

  [2/3] Replace "user-session=ubuntu" with "user-session=ubuntu-2d"

• sudo reboot

  [3/3] Restart your computer