Creating Help Files Compatible with Windows 3.0 and 3.1

The information in this article applies to:

• Microsoft Windows Software Development Kit (SDK) for Windows versions 3.1 and 3.0

SUMMARY

Windows help files are a convenient tool for documenting applications and systems. Because Windows versions 3.0 and 3.1 have different help engines, files that are optimized for use under Windows 3.1 cannot be used under 3.0. The Windows 3.1 Software Development Kit (SDK) includes help compilers to build help files compatible with both help engines. It also includes the 3.1 version of the help engine (WINHELP.EXE) as a redistributable file. By shipping the new help engine with their applications, developers can take advantage of the new help features in applications built to run under Windows 3.0.

MORE INFORMATION

Because the functionality of the Windows 3.1 Help engine (WINHELP.EXE) is so much greater, it is usually preferred to build help files to take advantage of such new features as metafiles, tables, segmented graphics, secondary help windows, and macros. If a help source file is designed for these features, it usually cannot be compiled using the 3.0 version of the help compiler (HC30.EXE).

Because designing and maintaining two help systems is usually not desirable, many programmers may opt for using only the Windows 3.0 Help features. Earlier files built with HC30.EXE work with the Windows 3.1 Help engine, but help files compiled with the Windows 3.1 Help compiler (HC31.EXE) cannot be used with the Windows 3.0 Help engine.

A better solution is to design for and use the Windows 3.1 features, compiling the file with HC31.EXE. The application's installation must then include the new Windows Help engine and instructions (or program support) to install it. Failure to use the correct help engine causes the Windows 3.0 version of Windows Help to issue an error indicating that the help file is incorrect.

The Windows 3.1 SDK comes with a number of redistributable files, two of which are WINHELP.EXE and WINHELP.HLP. These files are in the "redist" subdirectory in the directory where the SDK is installed. Because the redistributable file installation is optional when the SDK is installed, this directory may not exist. The files are also in the normal Windows directory and can be copied from there for redistribution.

WINHELP.EXE is the actual help engine for Windows. WINHELP.HLP is the help file for Windows Help and should be distributed with the .EXE to ensure that users have instructions available for using the new help engine. Both of these files should be installed in the Windows load directory on the target disk. They will replace the existing Windows 3.0 files. Within a Windows installation application the Windows directory path can be obtained using the GetWindowsDirectory() API function.