Pros: Powerful and quite easy to use, supports a batch conversion and supports advanced PDF export options.

Cons: It should provide us a convert button. As soon as you select the destination folder to save the converted file, it will start conversion automatically, which is not friendly.

Convert your Windows HTML Help files (*.chm) to PDF format is a good way to keep them from being revised. ABC Amber CHM Converter is a good choice to convert CHM file to PDF file. See a screenshot of this program: 

ABC Amber CHM Converter supports a batch conversion, so, you could add a folder to this program and click convert, it will convert several documents simultaneously, which is quite convenient when you have many CHM files need converting.

Use ABC Amber CHM Converter to convert CHM file to PDF file, it will keep the structure of CHM file, extract pictures and maintain hyperlinks.

There are also some useful features. For instance, it supports advanced PDF export options. You could set Owner password - password required for changes, User password - password required to open PDF and set many other parameters to prevent your PDF files from being revised easily.

System Requirements:
The setup file of this program is 1.92MB - such a light weight program that the hardware requirements could almost be ignored. However, when I used this program to convert a CHM file to PDF file, it occupied much system resource, and the conversion speed is much slower than many other CHM to PDF converters, for example, Document2PDF Pilot.

Conclusion:
ABC Amber CHM Converter is powerful but occupies much system resource and offers us slow conversion speed. I wish in the next version, designers could solve these problems and add a convert button.