After I've installed Ubuntu 12.04 my graphic card driver wasn't recognized. To fix this
I've installed "mesa-utils" package and my graphic driver now it's recognized.
On browsers (Chrome, Firefox), I have the impression that the images are a little bit pixelated, but just only in browsers because when I'm using a image viewer app the images seems to render proper. Is there a way to check if my graphic card is the right one and it's working proper? Thanks!
Later edit: I'm using a Lenovo B570e model.