Windows1.03 1.03

Windows 1.0 was the first release of what eventually made it onto almost every desktop computer in the entire world. Many of you are probably unaware of this release from 1985; conceived from ideas found in the original Lisa/Macintosh and Xerox Star system, Windows 1.0 was Microsoft's attempt at a graphical multitasking operating environment for the IBM PC.

The earliest known appearance of "Microsoft Windows" was in a 1983 Byte Magazine, and it was heavily promoted at the Fall 1983 Comdex. It was marketed as a response to GUI environments such as Digital Research GSX, VisiCorp Visi On, and Apple Macintosh, although the first completed release was not until late 1985.

Windows 1.0x features co-operative multitasking, tiled windows, ability to launch and integrate with DOS programs, runs on top of existing DOS, supports 8088 based PCs with IBM CGA, Hercules Monochrome, and IBM EGA video.

It was followed up by Windows 2.x.

Release notes

There are two known, slightly different, retail US versions of 1.03. They differ only in that the 08-24-86 version has a slightly different USER.EXE than the 08-21-86 version. The 08-24-86 version (newer user.exe) is verified to have shipped on retail Microsoft disks. The 08-21-86 (older user.exe) version is confirmed to have shipped on at least some OEM disks and may or may not have shipped on retail Microsoft disks.

It is not currently known what code difference actually does, if anything.

It appears the DEC Rainbow version may not have been commercially distributed, hence factory original disks may not exist.