At this point, if you are still using Ubuntu 12.04, either add the Oibaf PPA or upgrade to the Raring Enablement Stack.
Raring LTS Enablement Stack: sudo apt-get install --install-recommends linux-generic-lts-raring xserver-xorg-lts-raring libgl1-mesa-glx-lts-raring
Oibaf PPA: sudo add-apt-repository -y ppa:oibaf/graphics-drivers; sudo apt-get update; sudo apt-get upgrade -y; sudo apt-get dist-upgrade -y
At this point, if you are still using Ubuntu 12.04, either add the Oibaf PPA or upgrade to the Raring Enablement Stack.
Raring LTS Enablement Stack: recommends linux-generic- lts-raring xserver- xorg-lts- raring libgl1- mesa-glx- lts-raring
sudo apt-get install --install-
Oibaf PPA: graphics- drivers; sudo apt-get update; sudo apt-get upgrade -y; sudo apt-get dist-upgrade -y
sudo add-apt-repository -y ppa:oibaf/