Download and Fix AuthExt.dll

Sometimes Windows system displays error messages regarding corrupted or missing AuthExt.dll 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 AuthExt.dll file can therefore effect in failed execution of the started process.

AuthExt.dll file Authentication Extensions. The file was developed by for use with software. Here you will find detailed information about the file and instructions how to proceed in the event of AuthExt.dll related errors on your device. You can also download AuthExt.dll file compatible with Windows 10, Windows 8.1, Windows 8 devices which will (most probably) allow you to solve the problem.

For Windows Compatible with: Windows 10, Windows 8.1, Windows 8

File info

General information
Filename AuthExt.dll
File extension DLL
Description Authentication Extensions
Program Microsoft® Windows® Operating System
Author Microsoft Corporation
MIME type application/octet-stream
File type Dynamic link library
System Windows NT 32-bit
Copyrights © Microsoft Corporation. All rights reserved.
Character set Unicode
Language cod English (U.S.)

There are various types of errors related to AuthExt.dll file. AuthExt.dll 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 AuthExt.dll file. If you encounter one listed below (or similar), please consider the following suggestions.

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



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


Problems related to AuthExt.dll 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 AuthExt.dll 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.

AuthExt.dll 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 AuthExt.dll 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 AuthExt.dll 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 AuthExt.dll 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 AuthExt.dll file. After an error related to%fileextension% file has been discovered, the program attempts to automatically replace the AuthExt.dll 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 AuthExt.dll 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 AuthExt.dll 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 AuthExt.dll file

The last solution is to manually download and replace AuthExt.dll 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 AuthExt.dll file.

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

  • Windows 10: C:\Windows\System32\
  • Windows 8.1: C:\Windows\System32\
  • Windows 8: 1: C:\Windows\System32\

If the steps did not solve your AuthExt.dll 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 AuthExt.dll
System Windows 10
File size 52736 bytes
Date 2017-03-18
File details
MD5 ee5a76cc4abc8a5f51939ac2e67cc6bd
SHA1 56ca3c325b765f0a32929acd08fdcaebab3f50ed
SHA256 2ae34c035ff2285627ef36f78935a3124b6b6c4276c65aab5d0623814ef1be94
CRC32 0d62e643
Example file location C:\Windows\System32\
Filename AuthExt.dll
System Windows 8.1
File size 31232 bytes
Date 2014-11-21
File details
MD5 9e2d86747b843e887529655ffe40b900
SHA1 5d9e6fae1a68a0c224578a91083e276d75b43173
SHA256 3015795025248935cd299f0bbd5f892b8e6d3c483745adde648ddaf7972f97b1
CRC32 ac0e9e1e
Example file location C:\Windows\System32\
Filename AuthExt.dll
System Windows 8
File size 27136 bytes
Date 2012-07-26
File details
MD5 ef7701010381d1468703544ff5b48992
SHA1 f591c507ebb168092349145dee02c8e4c1d6bf7f
SHA256 9cec24e2164ac6eef74b56d0d12592ec6cef73ba87880498d881d9ab42c2b130
CRC32 8dcbdd69
Example file location 1: C:\Windows\System32\