Linux is the free operating system that is widely used to run Internet servers and increasingly on desktop computers as an alternative to Windows. Linux is secure and very powerful, plus it runs faster than Windows. There are several very good Linux choices for dual-booting with Windows. I particularly like Kubuntu - a flavor of Linux that looks and works much like Windows. http://kubuntu.org. You can download it or get a free CD shipped to you. Kubuntu (and it’s brother Ubuntu) comes with an installer that will create a dual-boot machine so you can use both Linux and Windows.