Go to Tools - VSdocman menu or press VSdocman button on standard toolbar. VSdocman dialog appears, select Options pane. Set Miscellanous - Environment page.
Path to CHM compiler hhc.exe
To create a CHM file, you need the free CHM compiler utility called hhc.exe. This simple command line tool is used by VSdocman when you compile documentation to CHM output format. The utility is a part of free HTML Help Workshop from Microsoft. If you have Visual Studio installed, you probably will not need to install it.
Starting with VS 2012, the Visual Studio installer automatically installs a minimalistic version of HTML Help Workshop. VSdocman will find it and you don't need to install anything. It may however happen, that during the compilation you'll get the following error:
HHC6003: Error: The file Itircl.dll has not been registered correctly.
The best way to fix it is to download and install the HTML Help Workshop.
This program is usually located in C:\Program Files (x86)\HTML Help Workshop folder. VSdocman tries to find the path automatically when started for the first time. You can also use Auto-find button anytime later. If it fails, you can do it manually. If you cannot find the file, you probably have not installed HTML Help Workshop. You can download it from http://www.helixoft.com/vsdocman-faqs/where-can-i-download-chm-compiler-hhc-exe.html
You don't need to install HTML Help Workshop if you don't want to generate CHM output.
Path to HxS compiler HxComp.exe
HxComp.exe is a compiler of Help 2 documentation (VS 2005 and 2008 help) which is used by Help 2 template when you generate Help 2 output. For VS 2005/2008 it is a part of Visual Studio 2005/2008 SDK which contains the Help 2 SDK. This program is usually located in C:\Program Files\Microsoft Help 2.0 SDK folder.
VSdocman tries to find that path automatically when started for the first time. You can also use Auto-find button anytime later. If it fails, you can do it manually. If you cannot find that file, you probably have not installed VS SDK. You can download it from http://www.helixoft.com/vsdocman-faqs/where-can-i-download-hxcomp.exe.html
You don't need to install VS SDK if you don't want to generate Help 2 output.