Ubuntu update "Some Index Files Failed to Download"

I have bean using Ubuntu on my pc @ work for a while now, when i tried to re-install lamp from ubuntu repositories, i run into a problem when i try to install through "apt-get", the error that says "Failed to Fitch, Some Index Files Failed to download... it looks like this:

So i did search google to find a solutions, and after a long search i found a simple solution that worked for me, but i am sharing it here in a very simple way with pictures so that it will save someone day out there...

The Solution:
You will need to Reset the "sources.list" file and to do that you will follow the nex steps:
  1. Open Terminal
  2. type "software-properties-gtk", Then Press Enter, it will open the below screen for you
  3. Click the "Revert" Button on the right bottom
  4. Click the Close Button and then allow to to update
  5. Now Close all the windows and go back to the Terminal, and type "sudo apt-get update", so that you can update and it should work.