Winows 3.1x is the fourth major release of the Microsoft Windows operating environment. Several editions were released between 1992 and 1994, succeeding Windows 3.0. This family of Windows can run in either Standard or 386 Enhanced memory modes. The exception is Windows for Workgroups 3.11, which can only officially run in 386 Enhanced mode. This version of Windows was and still is the basis for making PCs necessary, practical, and much more user-friendly.