How to Download and Fix authm.CHM?

Sometimes Windows system displays error messages regarding corrupted or missing authm.CHM files. Situations like that can occur, for example, during a software installation process. Each software program requires certain resources, libraries, and source data to work properly. Corrupted or nonexistent authm.CHM file can therefore effect in failed execution of the started process.

authm.CHM file Compiled HTML Help. The file was developed by Microsoft for use with Windows software. Here you will find detailed information about the file and instructions how to proceed in the event of authm.CHM related errors on your device. You can also download authm.CHM file compatible with Windows 8, Windows 7, Windows Vista devices which will (most probably) allow you to solve the problem.

For Windows Compatible with: Windows 8, Windows 7, Windows Vista

File info

General information
Filename authm.CHM
File extension CHM
Type Compiled HTML Help
Description Compiled HTML Help
Program Windows 8
Software Windows
Author Microsoft
Software version 8
MIME type application/x-chm
Language cod English (U.S.)

There are various types of errors related to authm.CHM file. authm.CHM file may be located in wrong file directory on your device, may not be present in the system, or may be infected with malicious software and therefore not work correctly. Below is a list of most common error messages related to authm.CHM file. If you encounter one listed below (or similar), please consider the following suggestions.

  • authm.CHM is corrupted
  • authm.CHM cannot be located
  • Runtime Error - authm.CHM
  • authm.CHM file error
  • authm.CHM file cannot be loaded. Module was not found
  • cannot register authm.CHM file:
  • authm.CHM file could not be loaded
  • authm.CHM file doesn't exist



Application could not be started because authm.CHM file is missing. Reinstall the application to solve the problem.


Problems related to authm.CHM can be addressed in various ways. Some methods are meant only for advanced users. If you don't have confidence in your skills, we suggest consulting a specialist. Fixing authm.CHM file errors should be approached with utmost caution for any mistakes can result in unstable or unproperly working system. If you have the necassary skills, please proceed.

authm.CHM file errors can be caused by various factors, so its is beneficial to try to fix them using various methods.

Step 1: Scan your computer for any malicious software

Virus Scan

Windows files are commonly attacked by malicious software that prevents them from working properly. First step in addressing problems with authm.CHM file or any other Windows system files should be scanning the system for malicious software using an antivirus tool.

If by any chance you don't have any antivirus software installed on your system yet, you should do it immediately. Unprotected system is not only a source of file errors, but, more importantly, makes your system vulnerable to many dangers. If you don't know which antivirus tool to choose, consult this Wikipedia article – comparison of antivirus software.

Step 2: Update your system and drivers.

Windows Update

Installing relevant Microsoft Windows patches and updates may solve your problems related to authm.CHM file. Use dedicated Windows tool to perform the update.

  1. Go to the Windows "Start" menu
  2. Type "Windows Update" in the search field
  3. Choose the appropriate software program (name may vary depending on your system version)
  4. Check if your system is up to date. If any unapplied updates are listed, install them immediately.
  5. After the update has been done,restart your computer in order to complete the process.

Beside updating the system, it is recommended that you install latest device drivers, as drivers can influence proper working of authm.CHM or other system files. In order to do so, go to your computer or device producer's website where you will find information regarding latest driver updates.

Step 3: Use System File Checker (SFC) tool

System File Checker

System File Checker is a Microsoft Windows tool. As the name suggests, the tool is used for identyfing and addressing system file related errors, including those related to authm.CHM file. After an error related to%fileextension% file has been discovered, the program attempts to automatically replace the authm.CHM file with properly working version. To use the tool:

  1. Go to the Windows "Start" menu
  2. Type "cmd" in the search field
  3. Locate "Command Prompt" result – don't run it yet:
  4. Click the right mouse button and select "Run as Administrator" option
  5. Type "sfc /scannow" in console prompt to start the program and follow the instructions

Step 4: Restoring Windows system

Windows Recovery

Another approach is to restore system to previous state, before the authm.CHM file error occured. In order to restore your system, follow the instructions below

  1. Go to the Windows "Start" menu
  2. Type "System Restore" in the search field
  3. Start the system restore tool – it's name may differ depending on version of the system
  4. The application will guide you through the process – read the messages carefully
  5. After the process has finished, restart your computer.

If all the above-mentioned methods failed and the authm.CHM file problem has not been resolved, proceed to the next step. Remember that the following steps are intended only for advanced users.

Download and replace authm.CHM file

The last solution is to manually download and replace authm.CHM file in appropriate folder on the disk. Select file version compatible with your operating system and click the "Download" button. Next, go to your web browser's "Downloaded" folder and copy the downloaded authm.CHM file.

Go to the folder where the file should be located and paste the downloaded file. Below is the list of authm.CHM file example directory paths.

  • Windows 8: C:\Windows\Help\mui\0409\
  • Windows 7: C:\Windows\Help\mui\0409\
  • Windows Vista: C:\Windows\Help\mui\0409\

If the steps did not solve your authm.CHM file problem, you should consult a professional. A probability exists that the error(s) might be device-related and therefore should be resolved at the hardware level. A fresh operating system installation might be necessary – a faulty system installation process can result in data loss.

File versions list

Filename authm.CHM
System Windows 8
File size 35168 bytes
Date 2012-07-26
File details
MD5 f0630a546d08e8f47c896f4f96969904
SHA1 ba5fc14ca139bd9bd1121ca17d964cd00502457f
SHA256 8912ffefe5afa037fc757439a23af93f79c83444ce412405d05415529ffea0f7
CRC32 47d854b9
Example file location C:\Windows\Help\mui\0409\
Filename authm.CHM
System Windows 7
File size 112877 bytes
Date -0001-11-30
File details
MD5 9dba0cb71af57c68b1a9a5761b42f001
SHA1 7c16e41a4f28410325bd4debe83ae21df6cf043f
SHA256 59e77a8945095cf63361e8571dd4f041f02b6c35cb8201793e6cbfd8d7024aec
CRC32 4753407a
Example file location C:\Windows\Help\mui\0409\
Filename authm.CHM
System Windows Vista
File size 115151 bytes
Date -0001-11-30
File details
MD5 0fbc436904f8bf8abf8bee3321cccaed
SHA1 aae66c37c4531ab83320b41d0aa338babcc7c069
SHA256 1bd43872e45babae9721a5eb0a1dd54ff501e7d013020310de8ac4a1d780c835
CRC32 bfc4f349
Example file location C:\Windows\Help\mui\0409\