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 Media. In Windows 8 and later the game is not included, but a free equivalent developed by Arkadium it is available from the Windows Store.
The goal of the game is to uncover all the squares that do not contain mines without being "blown up" by clicking on a square with a mine underneath. The location of the mines is discovered by a process of logic. Clicking on the game board will reveal what is hidden underneath the chosen square or squares (a large number of blank squares may be revealed in one go if they are adjacent to each other). Some squares are blank but some contain numbers (1 to 8), each number being the number of mines adjacent to the uncovered square. To help avoid hitting a mine, the location of a suspected mine can be marked by flagging it with the right mouse button. The game is won once all blank squares have been uncovered without hitting a mine, any remaining mines not identified by flags being automatically flagged by the computer. However, in the event that a game is lost and the player mistakenly flags a safe square, that square will either appear with a red X covering the mine (denoting it as safe), or just a red X (also denoting it as safe). The game board comes in three set sizes: beginner, intermediate, and expert, though a custom option is available as well.
In early versions of the game, a cheat code let players peek beneath the tiles.
In 2003, Microsoft created a variation called Minesweeper Flags in MSN Messenger, which is played against an opponent with the objective to find the mines rather than the surrounding squares.
The game's color scheme changed with the release of Vista (from gray to either blue or green). The icons were updated to match the Aero look. It also came with a more peaceful "flower" motif to replace the landmines. This iteration of Minesweeper was created by Oberon Media.
Microsoft removed Minesweeper from Windows 8 and instead published a free equivalent on its Windows Store. The new version is developed by Arkadium and is ad-supported. The initial release was supported by 30 second video ads. Later releases had monthly and annual subscription options to remove the ads. Multiple news outlets criticized the change as greedy. This version updates both motifs. Daily challenges and an adventure mode were also added.
Business Insider called the game an "iconic part" of the Windows operating system.