How to fix the Screen brightness problem in Ubuntu

Though there are very large number of users of Microsoft windows Operating System but in the market there exist other operating systems as well. one of those operating systems is "Ubuntu". 

It is an open source operating system so free of cost for user. Though it has also a beautiful design and light weight OS but one problem users usually faces is missing drivers. 

One of those drivers is brightness control. 

so how to get rid of this problem, see below. 

First of all open the terminal by pressing: 

Ctrl+Alt+T 

then paste the following command in the terminal and press enter 

ls /sys/class/backlight 

after that put the following command and press enter 

sudo touch /usr/share/X11/xorg.conf.d/20-intel.conf 

/ 

enter your password, then paste the below command and hit the enter  

sudo gedit /usr/share/X11/xorg.conf.d/20-intel.conf 

An editor will open and paste the following lines in the editor and save them. 

Section "Device" 

        Identifier  "card0" 

        Driver      "intel" 

        Option      "Backlight"  "intel_backlight" 

        BusID       "PCI:0:2:0"EndSection 

after this Log Out and Log In back. 

That’s it. 

 here are the screen shots.