Windows 1.0 DR 5

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

"DR5" is the earliest release known to still exist. If you think you have found an earlier build, please see our contributions section!

This was the 5th pre-release of Windows given to developers. It contained sample applications, some with source code. This requires MS-DOS 2.x or 3.0 to run. A serial or bus mouse is also required.

CGA and Hercules graphics support was included in both.

Installation instructions

PCem is known to run this. Configure PCem to emulate an "XT" style machine with a serial mouse. You will need to create a hard disk in PCem to use, 32 sectors, 16 heads and 30 cylinders will get you an 8MB hard disk. You will need to install DOS before Windows DR 5.

To switch from default CGA graphics to Hercules, do the following on command line:

  • path C:\windows\bin
  • cd C:\Windows\test
  • drivers HERCULES

You can swap back by running drivers IBMCOLOR to go back to CGA.

VMWare is not compatible with how this software uses CGA graphics. Neither VMWare nor Virtualbox emulate serial mice. We recommend that you do NOT use VMWare or Virtualbox. We recommend PCEm or PCE instead.

Screenshots courtesy of ToastyTech

Product type
Release date
Wed Oct 31 1984
End of life date
Wed Jul 31 1985
Minimum CPU
Intel 8088/8086 at 1MHz
Minimum RAM
Minimum free disk space
User interface
Download count
169 (15 for release)


Download name Version Language Architecture File size Downloads
Microsoft Windows 1.0 (Developer Release 5) DR 5 Prerelease English 257.78KB 15


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