Compiler messages:

It is a good idea to leave all these messages activated as they make it much easier to identify problems when you are publishing.

Handling of dead links:

These settings define how Help+Manual deals with dead hyperlinks created when you exclude topics from your build without also excluding links to them in other topics.

Silently include linked topics:
Excluded topics will be exported anyway if they are referenced in links in other topics in your project.Topics exported in this way do not have TOC entries – they are exported "invisibly" and will only be displayed when the user clicks on the links referencing them.

Remove link:
Removes the hyperlink from the text, leaving only plain text. This is really only recommended for testing purposes because the dead links may not make sense in your text if they are inactive.

Allow links to be dead:
This option does nothing. The links are not changed and the user will either get an error message or nothing at all will happen when they click on the links.

Tolerant handling of Asian languages:

Allows you to publish projects in Asian languages on Windows systems whose language does not match the language of the help project. Some features in the help generated may not work correctly, however (Search, Index). To test these features properly you need a version of Windows whose language or at least the system locale matches that of the project you are compiling. This is necessary because the Microsoft CHM format does not use Unicode and it needs support from the operating system to display languages with special character sets correctly.

If you are not using a version of Windows matching your Asian language you must set the system locale to the correct language, otherwise the HTML Help compiler will not work properly because it is not a Unicode program; it needs support from Windows to be able to handle these character sets correctly. To do this open the International settings in the Windows Control Panel. The setting is in the Advanced tab. In Windows XP it is called "Language for non-Unicode programs", in later versions of Windows it is called System Locale.

You need to restart Windows after changing the locale.  

Location for temporary files:

Enables you to specify a different drive and folder for storing the temporary files generated while publishing a number of output formats (CHM, ePUB, Kindle, eWriter, Visual Studio Help). In some cases this can speed up the publishing process, particularly if your project is on a network drive.

See Optimize Publish Speed for details.

HTML Help compiler:

The paths to the Microsoft compiler for HTML Help/CHM files. To get this you need to download the free Microsoft HTML Help Workshop package.  Visit this page for the download link for the correct version:

Microsoft HTML Help Workshop download

Warning:
When you install HTML Help Workshop you will get a confusing message saying that your computer "already has a newer version of HTML Help". This is an error in the Microsoft installer and is not relevant to the HTML Help Workshop program or the compiler. Both have installed correctly when you see this message.

Microsoft Help 2.0 compiler:

Location of Visual Studio Help 2008 compiler for the Microsoft Help 2.0/HXS help format (VS Help 2010 does not require a compiler). You can only get this compiler as part of Visual Studio.

Note that Visual Studio Help is only relevant for programmers documenting Visual Studio .NET components. It is irrelevant for all other purposes and cannot be used as a general help or documentation format for application programs.

Amazon Kindle compiler:

Location of the Amazon compiler that you need for publishing Kindle/Mobi eBooks. This compiler is included in the Amazon Kindle Previewer package, which you can download here:

Download the Amazon Kindle Previewer

Help+Manual will normally find the Kindle compiler automatically, but if it doesn't you can set its location here. It will normally be saved in:

Kindle Previewer version 2:

C:\Users\YourUserAccount\AppData\Local\Amazon\Kindle Previewer\lib\kindlegen.exe

Kindle Previewer version 3:

C:\Users\YourUserAccount\AppData\Local\Amazon\Kindle Previewer 3\lib\fc\bin

Resets all the settings and paths to the default values.

Search for  compilers:

Attempts to locate the necessary compiler executable files in your Program Files directory.