Windows 1.0 BYTE demo

Window Manager Demonstration 0.01 refers to an early demonstration of Microsoft Windows that was shown in the December 1983 issue of BYTE Magazine. The demo itself was made in September 1983 and was likely shown shortly after to members of the press. A picture of a disk containing the demonstration was posted to Twitter by ReflectiaX on 9 March 2022. It is the earliest build of Windows 1.0 and Microsoft Windows as a whole that is confirmed to exist.

The interface is very similar to Microsoft's DOS applications such as Word and Multiplan which were also released or in development at the time, with a command bar at the bottom of the screen, and featured overlapping windows that were later replaced by tiling windows. It remains unclear whether the build and applications demonstrated were actually fully functional or just cleverly crafted to create an illusion of a working system.