Intel integrated graphics in UBUNTU 12.04

System info says

Graphics: unknown.  
Driver: unknown,  
Experience: Standard.

Solution :

it means that it cannot acquire the information because glxinfo is not installed on the system.
You can install it by typing:

sudo apt-get install mesa-utils 

sudo apt-get install ppa-purge

sudo add-apt-repository ppa:xorg-edgers/ppa 

sudo add-apt-repository ppa:sarvatt/intel-sna

sudo apt-get update && sudo apt-get dist-upgrade

This will bring in newer versions of X Server, Mesa, and 
ATI/nVidia/Intel drivers. These have greatly improved effects for me, 
and I've encountered no problems.

But if they don't work for you, you can easily return to your prior state: 

sudo ppa-purge ppa:sarvatt/intel-sna
sudo ppa-purge ppa:xorg-edgers/ppa
sudo apt-get update && sudo apt-get dist-upgrade

SOURCE