Windows 1.0 was Microsoft’s first attempt to create a graphical user interface for MS-DOS. Technically, it was not a fundamentally new system, but only a graphical shell that ran on top of MS-DOS. But ...

Despite its age, Word for Windows hews closer to modern user interfaces. It’s successor, the DOS-based, mouse-enabled version or Microsoft Word launched in 1983.

In later years DOS provided the foundation for early versions of Microsoft Windows, the company’s first operating system with a graphical user interface.

Windows 1.0 was Microsoft's attempt at a friendlier, mouse-based user interface, one that let you switch between several programs simultaneously, and without having to quit and restart each one.

Microsoft and IBM continued to co-develop MS-DOS for many years; the version IBM licensed and sold on its PCs was called PC DOS, though for most of their history the two products were identical.

The user interface in the first versions of Windows. The MS-DOS Executive was superseded by Program Manager and File Manager in Windows 3.0. See Windows 1.0. THIS DEFINITION IS FOR PERSONAL USE ONLY.

PC-MOS, for those who weren't around in 1987, was a multi-user MS-DOS clone by Norcross, GA's The Software Link. It ran most standard DOS and 386's protected mode applications.

It might seem like the days of MS-DOS were a lifetime ago because…well, they basically were. Version 6.22 of the venerable operating system, the last standalone release, came out back in 1994… ...