You can download the old HtmlHelp compilers from
here (Note that the current compilers have a problem with certain file names)
Once you have
downloaded them, extract all the files from the .exe file (WinZip works for this) The download a patch file from
here and copy into the same directory. Extract and run the patch file and then run the MSI installer. When you've done this,
GenHelp will be able to find the
compiler.
(The patch file stops the installer requiring Visual Studio .NET to be installed)
