All computers run Windows.

While Microsoft would like you to believe this, it is not true. Windows is what we call an Operating SystemAn Operating System, or OS, is a piece of software that allows a computer how to interact with a person, and how to allow that person to use any devices (such as a keyboard or mouse) attached to the computer. If your computer was a car, you could think of your OS as being your brakes, steering wheel, turn signal, and other things that you use to control your car. There are a bunch of different OSes out there, just like there are different car manufacturers. Some OSes include: Microsoft Windows Apple MacOS X the many flavors of Linux, including: Ubuntu Fedora SuSE or OS. Its what allows you to "talk" to your computer, much like the steering wheel in your car. Other OSes exist besides Windows, although Windows is the most common, and used mainly for business applications. Other examples include: