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 until Windows 8. An updated version included in Windows Vista and Windows 7 was developed by Oberon Games. Another updated version was developed for Windows 8 and Windows 10 by Arkadium. In Windows 8 and 10 the game is not included by default, but it is available on the Windows Store.