If you have an Nvidia graphics card installed in your system here is a guide to update your drivers to the latest version for your graphics card. You can update the drivers by adding the Ubuntu x-swat ppa. If a new driver is released the old driver will be updated when updating your system.
To add the PPA and install the latest drivers open a terminal window (press Ctrl+Alt+T) and copy+paste the following lines:
sudo add-apt-repository ppa:ubuntu-x-swat/x-updates
sudo apt-get update
sudo apt-get install nvidia-current
When the installation is finished you can close the terminal window and reboot your system.