Tips to open CHM file

Can't open the CHM file? You are not the only one. Thousands of users face similar problems every day. Below you will find tips on how to open CHM files as well as a list of programs that support CHM files.

CHM file extension

File Name Compiled HTML Help Format
File Developer Microsoft
File Category Web Files

The CHM file is supported on 3 operating systems. Depending on your operating system, you may need different software to handle the CHM files. Below is a summary of the number of programs that support and open the CHM file on each system platform.

Operating systems
  • 7
  • 3
  • 2
  • 0
  • 0
  • 0

What is CHM file?

The .CHM file is a help file. It is a compressed program documentation. The documentation is written in HTML. This gives the possibility of placing images and internal (to places in the documentation) and external (e.g. to the manufacturer's website) hyperlinks. .CHM files can be viewed in a browser or by using special preview software. It mainly depends on the producer and author of the file with which applications you can open help. Some even allow preview only in the application.

How to open CHM file?

The main problem with Compiled HTML Help Format is that the CHM file is incorrectly associated with programs. Thus, when you open CHM, the program selection wizard or some other program starts. This problem can be easily remedied.

The first thing you should do is just "doubleclick" on the CHM file icon you want to open. If the operating system has an appropriate application to support it and there is also an association between the file and the program, the file should be opened.

Step 1. Install xCHM

An often overlooked issue is to make sure that xCHM is installed on the computer. To do this, enter the name xCHM into the system search engine. In the absence of an appropriate program, its installation in the vast majority of cases will fix the problem. Later in this article you will find a list of programs that can open CHM files.

Step 2. Create association of xCHM with CHM files

If, despite the installed application, the CHM file does not start in the xCHM application, you must create a file association. This option is available from the level of Properties of a specific file available in the context menu. The window will show, among other things, the type of the file and the information by which the program is used to launch the file. Using the "Change" button we can set the program to handle this type. The program should be visible in the window, otherwise it should be selected manually using the "Browse" button and the program installation directory should be indicated. The "always use the selected program ..." field will set the xCHM application as the default for handling the CHM file.

Step 3. Update xCHM to the latest version

The fault may also lie with the xCHM program, it is possible that Compiled HTML Help Format requires a newer version of the program. This can be done using the application (if it provides such options) or from the The xCHM team website and install the latest version.

Step 4. Check for the following problems with the CHM file

If the above steps do not help, you can assume that the file itself is not correct. This could be due to the file itself, the cleanest issues are:

The CHM file may be unusually small compared to the original file. This is most often caused by a problem while downloading the CHM file. Downloading the file again should fix the problem.
The computer may have fallen victim to a computer virus or hacker. A quick virus scan using an up-to-date antivirus program should clear up any doubts. If this is not possible, you can use the online scanner. For the best results, we will scan the entire operating system, not just our CHM file. However, remember that not every infected CHM file can be recovered, so it is important to take care of regular backups.
Older version of CHM file may not always be supported by the latest software version. Help should be sought from the software developer, as they usually recommend using free file converters or installing an older version of the program.
There can be many reasons for the failure. The repair method must be adapted to the type of file and damage. Sometimes the program itself has options to repair the most popular CHM file corruption. The easiest way to restore the file is from a backup or by contacting Microsoft, but this one can be expensive. Not all damage can be reversed.
The program can also signal the fact of encryption. The encrypted CHM files cannot be played on other computers than the one on which they were encrypted, they must be decrypted before using on another device.
The operating system protects files in some locations (e.g. the root of the system partition) against unauthorized access. The problem is only writing to the file, not reading it. If possible, you can try to move the CHM file to another location.
This problem only occurs with more complex files. In this case, the CHM file is blocked by the first application to open it. Closing other programs should help. Sometimes you have to wait for the session to the file CHM to close. Some anti-virus or backup software may occupy the CHM file for a certain period of time. If nothing helps, please reset the device.