From Altair to Windows 11: The Epic Evolution of DOS and Windows

DOS Operating System

In the 1970s, the Altair 8800 introduced the first personal computer, leading to the development of CP/M by Digital Research in 1976. IBM's PC project in 1980 sought an operating system, approached Bill Gates, and after negotiations acquired 86‑DOS (originally QDOS) from Tim Paterson, which Microsoft bought and released as MS‑DOS in 1981.

IBM licensed MS‑DOS per PC, while CP/M‑86 was priced higher and quickly lost market share. DR‑DOS and later Novell DOS followed, but MS‑DOS dominated until Microsoft shifted focus to Windows in the 1990s.

Windows Development History

Inspired by Xerox Alto and Apple Lisa, Microsoft released Windows 1.0 in 1985 as a graphical shell over DOS. Subsequent versions 2.0, 3.0, and 3.1 added features and achieved commercial success, leading Microsoft to abandon OS/2 and invest fully in Windows.

Key milestones include Windows NT (1993), Windows 95 (1995) with the Start menu, Windows 98, Windows 2000, Windows Me, Windows XP (2001), Vista, Windows 7, and the modern Windows 8, 10, and 11 series, each improving stability, security, and user experience.

Throughout the decades, Windows also expanded to server platforms (Windows Server 2003‑2016) and inspired numerous DOS derivatives such as FreeDOS, while the OS landscape continues to evolve.