general public on November 20, 1985, while the European version was released as Windows 1.02 in May 1986.

Its development began after Microsoft co-founder Bill Gates saw a demonstration of a similar software suite, Visi On, at COMDEX in 1982. The operating environment was showcased to the public in November 1983, although it ended up being released two years later. Windows 1.0 runs on MS-DOS,