TechNote

Decompiling a .CHM file

Issue

How do I decompile a Microsoft HTML Help (.CHM) file?

Solution

The HTML Help Studio tool provides an easy way to extract source files ("decompile") from a compiled Microsoft HTML Help file (.CHM). This is especially useful if you have a copy of the .CHM file, but do not have any of the source files. You can easily extract HTML topics, images, style sheets and other project files with this tool. To decompile a .CHM file:

From the Tools tab, double-click HTML Help Studio.
Navigate to the drive/folder where the .CHM file is located and double-click to select it.

Note: The HTML Help Studio dialog opens. It displays a list of files that are included in the compiled .CHM file. Everything is organized according to the folder structure used in the project source files. Folders that display plus boxes contain files.

Click the plus box to open the folder and view the files beneath. To view a specific file, select it from the list. Its content is displayed in the pane at the right side of the dialog.

Note: For certain types of files, the File Download dialog opens and you can choose to open or download the file.

Use the buttons across the top to navigate.

Extract the files you want to use from the .CHM by doing one of the following:

To extract a single file, select the file and click Extract .
To extract all files in a folder, select the folder and click Extract .
To extract all files in the .CHM, click Extract and select All Files.
In Extract To, select a destination for the file(s). If the destination folder (where you are extracting to) includes files with the same names as the ones you are extracting, select Overwrite Existing Files.
Click Extract.

Tip:

If you don't want to overwrite existing files, create a temporary destination folder and save the extracted files in this folder. After you've had a chance to review them, you can import them into your project folders.