Windows 1.0

From Computer History Wiki

Windows 1.0 was the first release of the Microsoft Windows environment for MS-DOS. It was not a commercial sucess, however it's design would influence the Presentation Manger for OS/2.

Windows 1.0 did not have overlapping windows, and it did not support PS/2 mice. It only ran in real mode. Needless to say this was *NOT* a popular version. It really only is of historical interest.

Even in a primitave state like this, it did have all of the components such as, USER, GDI, KERNEL etc..

There is an excellent article on the development of Windows 1.0 here.