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WinHelp was a help format that was first introduced in 1990 with Windows 3.0 and was supported until Windows XP . The format is not publicly documented, but has since been successfully decrypted using reverse engineering .


There were four versions of WinHelp:

  • Version 3.0: This was the first version that appeared with Windows 3.0. Served as a compiler HC.EXEor later HC30.EXE.
  • Version 3.1: This version appeared together with Windows 3.1 and supported macros, tables and numerous new image formats. Served as a compiler HC31.EXE.
  • Version 4.0: This version was part of Windows 95 and for the first time added a table of contents and a full text search. In addition, many of the limitations of previous formats (e.g. limitation of embedded images to 16 colors) have been lifted.
  • Multimedia Viewer: A format closely related to WinHelp that could contain any files (e.g. sounds, videos or executable files). The Multimedia Publishing Toolkit was available for creating help files in this format. The files had the file extension .MVBand needed a special viewer. This format was used by early versions of Microsoft Encarta , among others , but also by the MSDN Library .


WinHelp was based on the RTF file format . Help files could thus be created with any word processing program (e.g. Microsoft Word ). Special instructions for the compiler were written in curly brackets, and footnotes were used to subdivide the help file into sections. There was also a file with the file extension .HPJ. In terms of function, this corresponded to the makefiles of common programming languages ​​and contained, among other things, references to all files that were to become part of the compiled help file.

Images could either be inserted directly into the RTF (but were then limited to a size of 32 KB) or embedded as a reference, whereby the image is only inserted at runtime. Initially only bitmaps were supported , from Windows 3.1 WMF files and two proprietary image formats.

With the help of macros, functions could either be executed via a supplied DLL file, or the Windows API could be accessed directly from the help file. The latter in particular was later seen as a glaring security risk.

Optionally, a help file could define keywords which could then be searched using an index. From Windows 95 onwards there was also a real full-text search within help files.

The compilers were still limited to Windows 3.1 MS-DOS programs and thus to the 640 KB of conventional memory, even though Microsoft later published a version of the compiler that supported DOS extenders and was therefore no longer affected by this limitation. From Windows 95 onwards there was the graphical Help Compiler, which was also offered free of charge for download from the Microsoft website.

Replacement of the format

With Windows 98 , WinHelp was replaced by the HTML Help format , but WinHelp continued to be supported for reasons of backward compatibility.

Windows Vista no longer includes support for WinHelp. However, the viewer can be downloaded from the Microsoft website if required. A viewer for WinHelp for Windows 7 and Windows 8 can also be downloaded from the Microsoft website. Later versions no longer supported the WinHelp format.

Individual evidence

  1. Microsoft Knowledge Base - Q91025: Creating Help Files Compatible with Windows 3.0 and 3.1
  2. ^ Ray Duncan: Electronic Publishing with Windows Help . In: PC Magazine, 14, No. 1, Jan 10, 1995, pp. 246-249
  3. Microsoft Knowledge Base - Q85676: Windows Help and Help Compiler Capacity Limits
  4. Microsoft Knowledge Base - Q90291: Using Graphics Within a Help File
  5. Jim Mischel, Pete Davis: Undocumented WinHelp, Part 2: Find out how to make WinHelp do things it really wasn't meant to do. In: PC Magazine . 14, No. 15, September 12, 1995, pp. 536-541
  6. Microsoft Knowledge Base - Q84931: Use Extended Memory to Build Larger Windows Help Files
  7. How to Open .Hlp Files in Windows Vista, 7 or 8 Which Require Windows Help Program (WinHlp32.exe)?