Answer: Solitaire

When it comes to OS-bundled computer games, Microsoft’s Solitaire is, hands down, the most popular bundled game in the world. Although on the surface it may appear like the game was included with Windows just because it’s a simple and lightweight game, there’s a deeper back story.

Microsoft was concerned that most people, unfamiliar with graphic user interfaces, would find using Windows intimidating and be off put by the mouse. Solitaire was selected because the majority of people already knew how to play it and playing the game in a virtual space required extensive use of the mouse to click, drag, and drop the playing cards. In essence, the game came bundled with Windows to trick users into logging a lot of time playing with the mouse (becoming comfortable with it in the process).

Windows Solitaire first appeared in Windows version 3.0, released in 1990. It has undergone several updates over the years but, along with a host of other OS-bundled games, is still included with every version of Windows.