CHM File Extension

CHM file icon
Compiled HTML Help Format
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What is CHM file?

A .CHM file is a compiled online help file that is created using the help authoring tools, such as Microsoft HTML Help Workshop. The CHM file, which is an online help solution, comprises of images, text, hyperlinks that can be viewed by various programs supported on the Windows OS and on the web browsers, such as FireFox or Safari. Further, the CHM file can be converted into other formats, such as PDF, TXT, and other text formats, using various programs available online, including the Zamzar program. 

Programs which support CHM file extension

Below you will find an index of software programs that can be used to open CHM files divided into 3 categories according to system platform supported. Files with CHM suffix can be copied to any mobile device or system platform, but it may not be possible to open them properly on target system.

How to open file with CHM extension?

Problems with accessing CHM may be due to various reasons. On the bright side, the most encountered issues pertaining to Compiled HTML Help Format files aren’t complex. In most cases they can be addressed swiftly and effectively without assistance from a specialist. We have prepared a listing of which will help you resolve your problems with CHM files.

Step 1. Install xCHM software

The main and most frequent cause precluding users form opening CHM files is that no program that can handle CHM files is installed on user’s system. This issue can be addressed by downloading and installing xCHM or different compatible program, such as WinCHM, PowerCHM, ChmDecompiler. The full list of programs grouped by operating systems can be found above. One of the most risk-free method of downloading software is using links provided by official distributors. Visit xCHM website and download the installer.

Step 2. Check the version of xCHM and update if needed

If the problems with opening CHM files still occur even after installing xCHM, it is possible that you have an outdated version of the software. Check the developer’s website whether a newer version of xCHM is available. It may also happen that software creators by updating their applications add compatibility with other, newer file formats. The reason that xCHM cannot handle files with CHM may be that the software is outdated. The latest version of xCHM should support all file formats that where compatible with older versions of the software.

Step 3. Assign xCHM to CHM files

If you have the latest version of xCHM installed and the problem persists, select it as the default program to be used to manage CHM on your device. The next step should pose no problems. The procedure is straightforward and largely system-independent

Change the default application in Windows

  • Clicking the CHM with right mouse button will bring a menu from which you should select the Open with option
  • Select Choose another app → More apps
  • Finally select Look for another app on this PC, point to the folder where xCHM is installed, check the Always use this app to open CHM files box and conform your selection by clicking OK button

Change the default application in Mac OS

  • Right-click the CHM file and select Information
  • Open the Open with section by clicking its name
  • From the list choose the appropriate program and confirm by clicking Change for all....
  • Finally, a This change will be applied to all files with CHM extension message should pop-up. Click Continue button in order to confirm your choice.

Step 4. Ensure that the CHM file is complete and free of errors

Should the problem still occur after following steps 1-3, check if the CHM file is valid. Problems with opening the file may arise due to various reasons.

1. Check the CHM file for viruses or malware

Should it happed that the CHM is infected with a virus, this may be that cause that prevents you from accessing it. Immediately scan the file using an antivirus tool or scan the whole system to ensure the whole system is safe. If the scanner detected that the CHM file is unsafe, proceed as instructed by the antivirus program to neutralize the threat.

2. Ensure the file with CHM extension is complete and error-free

If you obtained the problematic CHM file from a third party, ask them to supply you with another copy. The file might have been copied erroneously and the data lost integrity, which precludes from accessing the file. If the CHM file has been downloaded from the internet only partially, try to redownload it.

3. Ensure that you have appropriate access rights

Sometimes in order to access files user need to have administrative privileges. Switch to an account that has required privileges and try opening the Compiled HTML Help Format file again.

4. Verify that your device fulfills the requirements to be able to open xCHM

If the system is under havy load, it may not be able to handle the program that you use to open files with CHM extension. In this case close the other applications.

5. Ensure that you have the latest drivers and system updates and patches installed

Regularly updated system, drivers, and programs keep your computer secure. This may also prevent problems with Compiled HTML Help Format files. Outdated drivers or software may have caused the inability to use a peripheral device needed to handle CHM files.

Do you want to help?

If you have additional information about the CHM file, we will be grateful if you share it with our users. To do this, use the form here and send us your information on CHM file.

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