Microsoft Windows 3.1x/WfW + Win32s

Windows 3.1x and Win32s overview

Windows 3.1x can be run from (on top of) DOS 3.xx - 6.22 or DOS 7.xx/8.xx (Windows 9x) - in Windows 9x - only in Standard/286 Mode ( /s).

Win32s is a subset of Win32 API for using 32-bit programs in Windows 3.1x, see below.
> View win 3.1 screenshots :) <
> View win 3.11 screenshots :) <

> Download Windows 3.1/3.11wfw HERE [WinWorld] :) <
> The Win32s compatibility list :) <
> Download Windows 3.xx updates & stuff :) <

Windows 3.1x 256-color VESA/VBE Compatible Driver

SVGAPatch: Tool to patch svga256.drv to make it VESA compliant. This may be useful if you want to run windows 3.1 or WfW 3.11 (in DOSEMU, for instance), but there exists no driver for your video adapter for these GUIs. SVGA256.DRV is included in WfW, but the driver itself can be downloaded from the net from various places (do a search for SVGA.EXE). Follow these steps:

Microsoft Win32s Win32 API Support

API Features supported:

except for features covered below:

In MS VC/C++ 1.x-4.x exist a full listing of functions supported in Win32s, see fourth column in LIB\win32api.csv table. Also there in help files, where Win32 API functions documented, it is clearly marked in what operating system such as Win95/NT or Win32s which API is supported or not. In addition - some specfic programming considerations when compiling for Win32s noticed there, such as maximum stack size and so on.

See CT sample in My projects for Win32s API demonstration. Only for latest Win32s version!

Win32s version history

Version history (source here):

NOTE 1: Microsoft Win32s version 1.30c is the latest version of the software that allows you to run Win32-based applications on Windows version 3.1 or Windows for Workgroups versions 3.1 and later. The Win32s upgrade is now available in the Microsoft Software Library (MSL) as Pw1118.exe.

Version 1.30 conflicts with 32-bit OS/2 environment, some emulators (f.e. MS Virtual PC 2004/2007) - use version 1.25a. Or use this method (source article is here: Installing a hybrid WIN32S 1.25/1.30 extension in WinOS/2 on OS/2 Warp 4):

  1. Install win32s 1.25
  2. Copy these files from Win32s 1.30 to %WINDIR%\SYSTEM\WIN32S directory:

NOTE 2: In Win32s 1.25 environment some features introduced in version 1.30 are not supported, such as:

Win32s MSKB ( Microsoft Knowledge Base ) Articles

MSKB: Win32s Version 1.x Bug/Fix Lists

BUG: Win32s 1.1 Bug List (Q113739)

The following is a list of known problem in Win32s version 1.1. Microsoft has confirmed these to be problems in Win32s version 1.1. Problems marked with a hyphen ("-") will be corrected in Win32s version 1.15. Problems marked with an asterisk ("*") will be corrected in Win32s version 1.2.

BUG: Win32s 1.25a Bug List (Q130138)

The following is a list of the known bugs in Win32s version 1.25 at the time of its release.

FIX: Win32s 1.25a Fix List (Q130139)

The following is a list of the known bugs in Win32s version 1.2 that were fixed in Win32s version 1.25.

FIX: Win32s 1.3 Fix List (Q133027)

The following is a list of the known bugs in Win32s version 1.25a that were fixed in Win32s version 1.3.

In addition, there were several bugs fixed in the Windows NT FP emulator. These fixes were are included in Win32s.

Win32s 1.30a Bug List at the Time of Its Release (Q138234)

This article lists the known bugs in Win32s version 1.30a at the time of its release.

Software support overview for Win32s

Making programs for Win32s? It is possible since Win32s API is a subset of Win9x/NT Win32 API.

  • OpenWatcon C/C++ ( FREE

  • MinGW C/C++, GNU C/C++

  • FreePascal (

  • Microsoft Visual C/C++ 32bit

  • Microsoft Visual FoxPro 3.0

  • Spyglass Mosaic Browser

  • Borland/Inprise products

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