Windows 1.0 is a 16-bit graphical operating environment that was released on 20 November 1985. It was Microsoft's first attempt to implement a multi-tasking graphical user interface-based operating environment on the PC platform. Windows 1.0 was the first version of Windows launched. It was succeeded by Windows 2.0.
Version 1.02, released in May 1986, was international and had editions in several European languages. Version 1.03, released in August 1986, was for the US- and international market, with enhancements making it consistent with the international release. It included drivers for European keyboards and additional screen and printer drivers. Version 1.04, released in April 1987, added support for the VGA graphics adapters of the new IBM PS/2 computers. At the same time, Microsoft and IBM announced the introduction of OS/2 and its graphical OS/2 Presentation Manager, which were supposed to ultimately replace both MS-DOS and Windows.
Windows 1.0 was superseded by Windows 2.0 in November 1987, but supported by Microsoft for sixteen years, until 31 December 2001.