FreeCell, as included in Microsoft Windows, is a computer implementation of the card game FreeCell.

The first computer version of the game is believed to have been created by Paul Alfille in 1978 for the PLATO system. Microsoft developer Jim Horne, who learned the game from the PLATO system, implemented a version with color graphics for Windows. It was first included with Win32s as an application that enabled the testing of the 32-bit thunking layer to ensure that it was installed properly. It was later included in Microsoft Entertainment Pack Volume 2 and later the Best Of Microsoft Entertainment Pack. However, FreeCell remained relatively obscure until it was released as part of Windows 95. In Windows XP, FreeCell was extended to support a total of 1 million card deals.

Today, there are FreeCell implementations for nearly every modern operating system as it is one of the few games pre-installed with every copy of Windows. Prior to Windows Vista, the versions for Windows were limited in their player assistance features, such as retraction of moves. The Windows Vista FreeCell implementation contains basic hints and unlimited move retraction, and the option to restart the game. Some features have been removed, such as the flashing screen to warn the player of one move remaining.

Microsoft Windows is a series of graphical interface operating systems developed, marketed, and sold by Microsoft.

Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces (GUIs). Microsoft Windows came to dominate the world's personal computer market, overtaking Mac OS, which had been introduced in 1984.

The most recent client version of Windows is Windows 7; the most recent server version is Windows Server 2008 R2; the most recent mobile version is Windows Phone 7.5.The most recent unstable release is Windows 8.

The term Windows collectively describes any or all of several generations of Microsoft operating system products. These products are generally categorized as follows:

The history of Windows dates back to September 1981, when Chase Bishop, a computer scientist, designed the first model of an electronic device and project "Interface Manager" was started. It was announced in November 1983 (after the Apple Lisa, but before the Macintosh) under the name "Windows", but Windows 1.0 was not released until November 1985. The shell of Windows 1.0 was a program known as the MS-DOS Executive. Other supplied programs were Calculator, Calendar, Cardfile, Clipboard viewer, Clock, Control Panel, Notepad, Paint, Reversi, Terminal, and Write. Windows 1.0 did not allow overlapping windows. Instead all windows were tiled. Only dialog boxes could appear over other windows.