How to open CHM file in Windows

How to open CHM file in Windows: The file in CHM format is intended for displaying help documentation. The compiled HTML help file (.chm) was developed by Microsoft.

A CHM (Compiled Help Modules) help file is opened by default by a utility built into the operating system. To open a file in this format, just double-click on the CHM file with the mouse, or open the file in an appropriate program, which has help information in the form of a file of this type, from the application’s control menu.

Next, the Windows operating system will launch the utility and open the compiled help file.

How else can you open a help file with a .chm extension? With the help of third-party programs, the CHM help file can be opened in programs: 7-Zip, Sumatra PDF, Caliber, and some others.

CHM file won’t open

In some cases, the .chm help file does not open:

• if the CHM file is located on a network drive, then to open the file you need to copy the help file to your computer;
• if the file name contains Cyrillic or special characters, then you need to rename the file, giving the file a name in Latin letters.

CHM file contents not showing

Another option is much more common: the CHM file itself is launched from the program, or immediately after clicking on the file, but the help content is not displayed. Only the content of the document is open.

I was inspired to write this article by an incident that happened to me. I wrote a review of the IrfanView program on the site. The program supports the Russian language, but the files for the Russification of the program are installed after the program is installed on the computer.

After installing the language pack, I ran the help file in the program, and saw that the contents of the CHM file were not displayed. The Windows operating system blocks the display of the Help file to protect your computer.

What to do? In fact, I know what to do, as I have already encountered a similar problem before. I thought that some users may also encounter this option to launch a document. The person hopes to get answers to their questions, but instead, they receive the empty contents of the help file, only the table of contents is displayed.

First you need to find the compiled help file in CHM format on your computer. In most cases, it is located in the installed program folder.

Next, right-click on the CHM file. In the context menu that opens, select “Properties”.

This will open the “Properties: filename” window. At the bottom of the window, you will see a warning: “Caution: This file was received from another computer and may have been blocked to protect your computer.”

Next, check the box next to “Unblock”, and then click on the “OK” button.

You can open the CHM help file again and see that the help content is now displayed.

Article Conclusions

A compiled HTML help file in CHM format can be opened with an operating system tool, or with third-party programs. In some cases, Windows locks the contents of a Help file to protect your computer, so the CHM file can be unlocked to display Help content.