Microsoft Minesweeper (formerly Minesweeper) is a minesweeper computer game created by Curt Johnson, originally for OS/2, and ported to Microsoft Windows by Robert Donner, both Microsoft employees at the time. First officially released as part of the Microsoft Entertainment Pack 1 in 1990, it was included in the standard install of Windows 3.1 in 1992, replacing Reversi from Windows 3.0. Microsoft Minesweeper has been included in all subsequent Windows releases except Windows 8.