original version of Microsoft Windows, which was announced in late 1983
and introduced in late 1985. Windows 1.0 was a DOS application that
provided a rather awkward graphical interface and windowing
environment. Its "MS-DOS Executive" was the launching pad for
applications that were displayed in side-by-side windows that could not
be overlapped with each other.
Microsoft first began development of the Interface Manager (subsequently renamed Microsoft Windows) in September 1981.
the first prototypes used Multiplan and Word-like menus at the bottom
of the screen, the interface was changed in 1982 to use pull-down menus
and dialogs, as used on the Xerox Star.
Microsoft finally announced Windows in November 1983
1.0 included a clipboard, calendar, clock, control panel, Notepad
editor, Windows Write and Windows Paint, but it was not very popular.