VirtualBox is a virtualization tool which allows us to install and run different OS like windows and linux. I had tried installing ubuntu10.04 over ubuntu 10.04. To install it in Ubuntu (10.04 for now): i. go to Ubuntu Software Center and search for Oracle VM VirtualBox, then click install. ii. Goto virtualbox.org -> Downloads and get the package that you need for your system (For e.g. ".deb" package for Ubuntu) iii. Install virtualbox from commandline: sudo apt-get update sudo apt-get install virtualbox-4.1 If writing the version number fails then trying without version number might work: sudo apt-get install virtualbox After installing the Virtualbox, we can install any Operating System over it. Installing a new OS is more or less similar to installing an OS in a new computer but you need to do some more before proceeding to install the new OS: i. Open the VirtualBox window, then Press New button and create a new Virtual Machine. ii. Specify the Name (e.g...