Windows 1.0 is a graphical personal computer operating environment developed by Microsoft.
Microsoft had worked with Apple Computer to develop applications for Apple's January 1984 original Macintosh, the first mass-produced personal computer with a graphical user interface (GUI) that enabled users to see user friendly icons on screen.
Windows 1.0 was released on November 20, 1985, as the first version of the Microsoft Windows line. It runs as a graphical, 16-bit multi-tasking shell on top of an existing MS-DOS installation. It provides an environment which can run graphical programs designed for Windows, as well as existing MS-DOS software.
Its development was spearheaded by the company founder Bill Gates after he saw a demonstration of a similar software suite known as Visi On at COMDEX.