Windows 1.0: how it was installed and how to run it today

Windows 1.0 came out in November 1985 and is not a complete operating system: it is a program that runs on top of MS-DOS. Here is how it was installed, and how hobbyists set it up today in an emulator (a program that imitates an old PC).

What you need

Windows 1.0 is a 16-bit shell (the part you click on) that runs on MS-DOS. It starts a program when you open its .exe file in a file list called the MS-DOS Executive. Windows are tiled side by side and cannot overlap.

How it was installed in 1985

You started a PC with MS-DOS, put the first Windows disk in a floppy drive and ran a DOS program called SETUP. Setup asked about your mouse, screen and printer (the exact prompts varied by version), copied files from several disks, and combined the core files into one image so Windows would start faster. Afterward you typed WIN at the DOS prompt to start it.

Set it up in DOSBox-X

DOSBox-X is a free emulator that can run DOS-based Windows. The steps below follow the DOSBox-X project's own Windows 1.0x guide, which also supplies a sample configuration file. See the DOSBox-X guide for installing Windows 1.0x (an external project wiki). The 86Box emulator is another choice if you want an accurate 8088-era PC.

1. Create a new, empty folder on your computer to act as the emulated C: drive. Do not use the top level of your real C: drive for this.
2. Inside it, make a folder named INSTALL and copy the contents of each of your Windows disks into it.
3. Start DOSBox-X with the sample configuration, then mount your new folder as drive C: as the guide describes.
4. Make the install folder act as the floppy drive.

   SUBST A C:\INSTALL

5. Switch to that drive by typing A: and pressing Enter.
6. Start Setup.

   SETUP

Answering Setup's questions

• Press Enter to accept the default choices where Setup offers them, including the install folder.
• If asked for a keyboard layout (version 1.02 and later), pick yours.
• For the mouse, choose Microsoft Mouse (Bus/Serial).
• For the screen on the retail version, choose EGA (more than 64K) with Enhanced Color Display. The IBM edition of 1.04 lists an IBM Personal System/2 Model 50, 60, 80 choice for VGA.
• When Setup asks for the next disk, press Enter. Because you copied the disks to a folder, you do not have to swap anything.
• Set up a printer only if you need one; you can skip it.

Check that it worked

1. Start DOSBox-X again with the sample configuration. Its startup commands look for the installed Windows (by default in C:\WINDOWS) and start it for you. If it does not, change to that folder yourself.
2. If you started it yourself, type WIN and press Enter. The MS-DOS Executive appears with a file list and menus.

If something goes wrong

Windows 1.0x can use only 640 KB of base memory. Retail versions have no PS/2 mouse or VGA support (only IBM's OEM 1.04 has them), so use a serial mouse and EGA. It also needs a DOS version lower than 4.0, which the sample configuration sets for you. For mouse, display and other symptoms, see Windows 1.0: running programs and fixing common problems. The next release is covered in Windows 2.x installation.

Frequently asked questions