Microsoft Windows 1.01, the first public version of Windows, was released on November 20, 1985. It is shown here running on an IBM PC XT (Model 5160) with a CGA Display. You can also run Windows 1.01 with an EGA Display.

The above simulation is configured for a clock speed of 4.77Mhz, with 256Kb of RAM and a CGA Display, using the original IBM PC Model 5160 ROM BIOS and CGA font ROM. Even though the CGA was a “Color Graphics Adapter,” the only CGA mode that Windows supported was the 640x200 2-color mode, hence its black-and-white appearance.

This PC XT configuration also includes a 10Mb hard disk with Windows 1.01 pre-installed.

NOTE: The Windows 1.01 mouse pointer can be controlled with your mouse, but only when your mouse is within the “CGA Display” window. This is a restriction imposed by your web browser, not PCjs.