Operating System(OS) is the heart of a computer.The very first software component that has to be installed in a system is the OS. Basic users will have only one OS in their system, obviously Windows. But advanced users like developers, programmers and other techs will have more than one OS running ,to delegate their work. Am not going to talk about either of them. This is all about people who are in the transition between a Basic User and Advance User. This first time, when you have your Windows CD/DVD(Original OfCourse!! :p) in your left hand and an Ubuntu Linux CD in your right hand, you are exactly in the entrance of a cross road, dont know which path to take.There will be a little fear about your documents because bad installation of a strange operating system might sweep your entire hard disk. Some people will have a regular back up practice, but some people (like me :p) will start looking for a media in their messy desk draw to have a back up, just before they start. Any how