Windows 1.0

Windows 1.0 (briefly codenamed Interface Manager) is a 16-bit graphical operating system developed by Microsoft Corporation and released to testers in July, 1985 as Windows 1.0 Premiere Edition. It runs as a graphical shell on top of an existing MS-DOS installation. Support was officially discontinued on December 31, 2001. Windows 1.0's first public release was Windows 1.01, while Windows 1.02 was the first international release.

Windows 1.0 offered limited multitasking. Some basic applications included with Windows 1.0 were Calculator, Calendar, Clipboard Viewer, Clock, Notepad, Reversi, Paint, Write, and Cardfile.