Welcome to HelpDeco V2.1

HelpDeco is a decompiler for Windows HLP files and multimedia titles. It proves this way that this description of the Windows HLP file format is correct.

HELPDECO.ZIP contains the 16/32 bit command line application HELPDECO.EXE and the SPLITMRB.EXE and ZAPRES.EXE utilities

HELPDC21.ZIP contains all the above including the source and file format description

A Windows front end is available to control HelpDeco

HELPDECO Command Program Launcher from Ian Duff.

A short description of the program:

HELPDECO.EXE dissects HLP help files of Windows 3.0, 3.1, 3.11, and '95 and many MVB multi media viewer titles into all files required for a rebuild using the appropriate help compiler HC30, HC31, HCP, HCW, HCRTF, WMVC, MMVC or MVC:

HPJ - help project file, use as parameter when calling help compiler
MVP - multi media project file, parameter for multi media help compiler
RTF - text file containing whole content of help file and all footnotes
PH - phrases file (same as produced by help compiler)
ICO - icon of help file if embedded
BMP/WMF/SHG/MRB - embedded pictures in appropriate format
Baggage - all baggage files contained in help file

Call HELPDECO from MS-DOS command line. Supply the name of help file to use, optional name of internal file, and options if appropriate. HELPDECO runs from Windows 95 or Windows NT command line as 32-bit application to handle larger help files.


Displays usage

HELPDECO helpfilename

Decompiles help file into all sources needed for a rebuild. All files are created in current directory (should be empty). Existing files will be overwritten without asking if option /y was specified. Options may be appended to the command, separated using blanks, as follows:


May be used to stop parsing macros for topic names. Help compiler will emit Warning 4131.


May be used to stop resolving browse sequences. Help source file than contains no + footnotes.


Turns off time consuming guessing of context names. Applicable when HELPDECO reports 'no context ids found' or when you are not interested in legible context ids. This doesn't affect functionality. During guessing HELPDECO tries to reconstruct context ids from topic titles and keywords. This may produce good results on some help files and no result at all on others, depending on autoring tool used or working method of help author.


If you want to see which context ids are guessed by HELPDECO...


HELPDECO tries to guess context ids from topic titles and keywords, possibly prefixed by idh_ or helpid_. If the help file was created using other prefixes, they may be added to the table using the /h prefix option.

/a [annotationfilename.ANN]

Adds all annotations from annotationfile as annotations of user ANN into RTF file. Default annotationfilename is helpfilename.ANN.

/s n

Splits output every n pages into a separate RTF file. For example HELPDECO helpdemo /s 100 decompiles helpdeco.hlp and creates different RTF files helpdem1.rtf, helpdem2.rtf,.. each containing no more than 100 topics.

HELPDECO helpfilename /r

Converts help file into RTF file of same appearance if loaded into WinWord as if displayed by WinHelp. To print or work with complete content. Specify additional option /n, if no page breaks should separate topics.

HELPDECO helpfilename /c

Generates a *.CNT file used by WinHlp32, containing all chapters that have titles assigned in the order they appear in the helpfile. This file should then be edited using HCW 4.00 or any text editor into a hierarchical order.

HELPDECO helpfilename /e

Lists all references to external help files.

HELPDECO helpfilename /e /f

Lists all references to external help files and titles of topics that contained these references.

HELPDECO helpfilename /p

Checks references to external help files. Referenced help file need to be available to HELPDECO. This call doesn't produce any new files and doesn't modify existing files. Errors are reported to stdout (screen).

HELPDECO helpfilename /d

Displays internal directory of help file. You may supply a *.MVB,*.M??, *.ANN,*.CAC,*.AUX file instead of a *.HLP file.

HELPDECO helpfilename /x

Displays hex dump of internal directory

HELPDECO helpfilename "internalfilename"

Displays internal file in appropriate format if known, else hex dump. You may redirect output into a file using >outfile.

HELPDECO helpfilename "internalfilename" /x

Displays hex dump of internal file

HELPDECO helpfilename "internalfilename" /x /t offset

Displays hex dump of internal file starting at offset, which may be specified in decimal or preceeded with 0x in hex.

HELPDECO helpfilename "internalfilename" filename

Exports internal file into filename

*.ANN, *.CAC, *.AUX

These files are formatted like helpfiles, but HELPDECO can only be used to display their internal directory or display or export internal files.

HELPDECO was written by Manfred Winterhoff, Geschw.-Scholl-Ring 17, 38444 Wolfsburg, Germany

If you have more questions, problems (or answers!), please feel free to send me an eMail to mawin@gmx.net

HELPDECO is based upon HELPDUMP from Pete Davis published in: The Windows Help File Format, Dr. Dobbs Journal, Sep/Oct 1993

Thanks to Holger Haase, who did a lot of work on picture file formats.

And thanks to Jürgen Müller for pointing out 32-bit differences.

Thanks to Bent Lynggaard for the information on help file free lists and his contribution on context id guessing.

See HELPFILE.TXT for a description of the Windows help file format as parsed by HELPDECO and related file formats like MRB/SHG.

The newest public version of HELPDECO is always available at my home page:


HELPDECO is freeware. Use at your own risk. No part of the program may be used commercially. No fees may be charged on distributing the program (shareware distributors keep off).

The use of parts of decompiled help files may constitute a violation of copyright law.

Version 2.1:

macros may contain rtf meta characters
Win95 topic names may contain (nearly) all characters
0x8000 in SWin->Maximize allowed
ForeHelp creates PhrIndex/PhrImage _and_ _empty_ Phrases file
HCRTF complained about > footnotes before # footnotes
macro parsing changed again

Version 2.0:

Guess context ids from titles and keywords based on idea of Bent Lynggaard
Recompiled 16 bit EXE without register calling convention. BC++ 3.1 bug.
Doesn't print last (stray) topic of HC30 help files
Can list entry points into this help file (option /l)

Version 1.9: faster & better than ever...

changed TopicPos, TopicOffset, Keyword maintenance
changed unhash to 40 bit integer arithmetic
fixed keyword footnotes [Bent Lynggaard]
no [ALIAS] in MVP files
no hidden text in option /r RTF files
some changes in font and stylesheet handling
corrects rounding error of HC31 on negative values
handles non-underlined topic jumps

Version 1.8: used some spare days to clean up the to-do list...

better tracking of TopicOffset during decompilation
lists and checks references to external files, shows referencing topics
can add annotations from .ANN file to decompiled .RTF file
fixed bug in handling of pictures containing JumpId-macro hotspots
changed parsing of macros (3rd attempt to guess what Microsoft did)
fixed bug in popup/jump to external file / secondary window
fixed bug in > footnote / |VIOLA internal file handling
fixed bug in keyword assignment
now removes LZ77 compression from exported SHGs/MRBs
recreates Win 95 (HCW 4.00) [MACROS] section from internal |Rose file
32 bit version available
handles LANGUAGE, [CHARTAB] and [GROUP] section of media view files

Version 1.7

removed unneccessary output statement

Version 1.6 can now check references to external help files plus:

duplicate macro names preceeding picture hotspot info skipped
does not write Win95 commands to multi-media help project files
changed unhash to circumvent Microsoft-C++ float rounding error
handles keywords defined inside topic text

Version 1.5

fixed static on buffer of TopicName function (affected HC30 files)

Version 1.4 fixes some bugs reported by different users:

buffer overflow in expanding LZ77&RunLen (byPacked 3) images fixed
embedded images {bmxwd} larger than 32k supported
extract topic names from jump into external file if no file specified
handles more phrases on HCRTF generated (Win95) help files
Windows 3.1 (HC31) |Phrases always Zeck compressed
LinkData2 buffer enlarged 1 byte to store trailing NUL character

Version 1.3

parses examples of {bmc} etc. statements contained in help text correctly
can now generate a *.CNT content file for Windows 95 / WinHlp32
Microsoft C: ctype macros (isalnum/isprint) don't work with signed char

Version 1.2 fixes some severe bugs introduced in version 1.1 and:

tells you which help compiler to use
collects multiple keyword footnotes into single lines
handles \r\n in COPYRIGHT
converts SPC-macro (but only in [CONFIG] section)
does not generate duplicate MAP-statements if possible
{button} and {mci,mci_left,mci_right} commands supported
[BITMAP]-section in HCRTF help files irritated transparent bitmaps

Version 1.1 now supports more features of Win95/HCRTF 4.00/WinHlp32:

Additional Win95 Macros (to extract original topic names)
[CONFIG:n] of Win95 supported (internal file |CFn)
Secondary windows with > footnote supported (internal file |VIOLA)
Transparent bitmaps supported (bmct,bmlt,bmrt)
Expanded internal limits as HCRTF allows larger items
Now does RunLen compressed device dependend bitmaps
Bugs in handling of metafiles removed
Bug in placement of pack(1) removed
Parsing of macros changed (is it really better now ?)