What Is Dual-Booting?

Dual-booting means installing two separate operating systems on the same computer. You can partition a single drive with one operating system on each, use one hard drive for each operating system, or spread things out among a few drives. For example you could dual-boot Linux and Windows or Linux and Mac OS.

Here is how dual-booting works. Your hard drive has on it what is called the Master Boot Record (MBR). The Master Boot Record is located in the first sector of your hard disk. The record contains your partition table as well as information to identify where and how your operating system will boot. Normally, with one operating system, the MBR just shoots right into the OS that you have on your hard disk. However, when you are dual-booting, the MBR first makes a stop at a program called a boot loader. The boot loader gives you a menu of choices so that you can choose which of the operating systems on your hard disk you want to boot into. If you make no choice, the default choice is chosen automatically after a set number of seconds. The labels for the operating systems, which one is the default, and how many seconds to wait are all configurable.

Why need  Dual-Boot?

A good portion of the rest of the world is using other operating systems, mostly Windows and Mac OS. Those people will send you files, design Web sites, provide multimedia content, write software, and do most everything else with those other two more popular operating systems in mind. Linux can handle most of that, but sometimes you will need to use Windows or Macintosh. You might receive an office document with formatting that looks funny when you open it in Linux. You might visit a Web site that has a lot of multimedia content that would just be too much trouble to make work in Linux for the few moments that you will be there. You might have a deep, abiding need to play the latest first-person shooter game that will not run in Linux. You might want a gradual change to your new OS. You might get the point by now with all these repetitive sentences I have just given you.