So you have heard of Linux, and especially about Ubuntu. You want to try it out, but you only have one computer, and it already has Windows as a main operating system. You don't want to replace Windows yet, because you're unsure about Ubuntu and Linux. No problem, Virtualbox is what you need. It helps you install Ubuntu and a whole lot other operating systems onto Windows without requiring you to remove Windows. Plus, you can always remove a virtual machine that Virtualbox adds easily, because all you have to do is to send the virtual hard drive of a virtual machine to a trash bin. Virtualbox and Ubuntu should be able to work on Vista, but in this video tutorial, I'm going to show you how to use these on Windows 7. There is one little spot in the video that I had cut it wrongly, and so it was a little lack of information -- here I try to explain ( edit /etc/shadow is not necessary, because you can do "passwd -l [your-account-name-here]").