Microsoft released Windows 1.0 in 1985 as its first version of the Windows operating-system line.
Windows 1.0 launched on November 20, 1985, after Microsoft had announced the project several years earlier. It provided a graphical environment that ran on top of MS-DOS, allowing users to work with tiled windows, menus, dialog boxes, icons, and a mouse rather than relying entirely on typed commands.
The release included early versions of applications such as Windows Write, Windows Paint, a calendar, a clock, a terminal program, and a game called Reversi. Its windows could not freely overlap, a limitation that distinguished the first release from later versions.
Windows 1.0 was not a replacement for MS-DOS; it depended on DOS to run. Windows 95 later became a major consumer milestone by integrating more of the operating-system experience, but it was released a decade after Windows 1.0.