Microsoft released Windows 1.0, its first graphical operating environment for MS-DOS, in 1985.
Windows 1.0 launched on November 20, 1985, after Microsoft had announced the project several years earlier. It provided a graphical layer over MS-DOS and included programs such as MS-DOS Executive, Paint, Notepad, and Calculator.
The first release looked very different from modern Windows. Windows could not freely overlap in the initial interface, and the system depended on MS-DOS rather than replacing it. Users navigated with a mouse as well as the keyboard, reflecting the growing influence of graphical interfaces.
Windows 1.0 is often confused with Windows 3.0, which achieved much broader popularity, or Windows 95, which introduced the Start menu and taskbar. Those were later releases. The 1985 date identifies Microsoft’s first publicly released Windows version.