Windows Ver.3.1

Released on April 6, 1992.

Windows 3.1, released on April 6, 1992, introduced a TrueType font system (and a set of highly legible fonts), which effectively made Windows a viable desktop publishing platform for the first time. Similar functionality was available for Windows 3.0 through Adobe Type Manager (ATM) font system from Adobe.

Windows 3.1 was designed to have backward compatibility with older Windows platforms. As with Windows 3.0, version 3.1 had File Manager and Program Manager, but unlike all previous versions, Windows 3.1 cannot run in real mode. It included Minesweeper as a replacement for Reversi (though Reversi was still included in some copies).

Windows 3.1 dropped real mode support and required a minimum of a 286 PC with 1 MB of RAM to run. The effect of this was to increase system stability over the crash-prone Windows 3.0. Some older features were removed, like CGA graphics support (although Windows 3.0's CGA driver still worked on 3.1) and compatibility with real-mode Windows 2.x applications. Windows 3.1 can run in Standard mode if installed with the VGA display driver. When installed with high resolution/high color driver, it only operates in 386 Enhanced Mode.

In 386 Enhanced Mode, windowed DOS applications gained the ability for users to manipulate menus and other objects in the program using the Windows mouse pointer, provided that a DOS application supported mice. A few DOS applications, such as late releases of Microsoft Word, could access Windows Clipboard. Windows' own drivers couldn't work directly with DOS applications; hardware such as mice required a DOS driver to be loaded before starting Windows.

Windows 3.1 also introduced the Windows Registry, a centralized database that can store configuration information and settings for various operating systems components and applications.

Windows 3.1 was the first version that could also launch Windows programs via Command.com.

Official support for Windows 3.1 ended on December 31, 2001.