Fix authui.dll Errors

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

authui.dll file Windows Authentication UI. 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 authui.dll related errors on your device. You can also download authui.dll file compatible with Windows 10, Windows 8.1, Windows 8, Windows 7, Windows 7, Windows Vista, Windows Vista devices which will (most probably) allow you to solve the problem.

For Windows Compatible with: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows 7, Windows Vista, Windows Vista

File info

General information
Filename authui.dll
File extension DLL
Description Windows Authentication UI
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 authui.dll file. authui.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 authui.dll file. If you encounter one listed below (or similar), please consider the following suggestions.

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



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


Problems related to authui.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 authui.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.

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

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

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

  • Windows 10: C:\Windows\System32\
  • Windows 8.1: C:\Windows\System32\
  • Windows 8: 1: C:\Windows\System32\
  • Windows 7: C:\Windows\System32\
  • Windows 7: C:\Windows\System32\
  • Windows Vista: ---
  • Windows Vista: ---

If the steps did not solve your authui.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 authui.dll
System Windows 10
File size 435712 bytes
Date 2017-03-18
File details
MD5 b7e877f6cec5c95cc87c330a4d099a59
SHA1 0a49fe9fc2c63385464cf062a575ac8e733a42f5
SHA256 2923c937c98d53eccc9e0da050d8cc7729a4e7a05255287e555b4c8056edd0f9
CRC32 4fdd003c
Example file location C:\Windows\System32\
Filename authui.dll
System Windows 8.1
File size 2459136 bytes
Date 2014-11-21
File details
MD5 61d8654b70cc1bb59090ff23bf3216c3
SHA1 6ddcfcbed6ece9e47a0231af05cf77f93fdbae4e
SHA256 285e3a8111cf54080dd922ed8c84cbfe4b25900ce2c081ee950a6a345767cefc
CRC32 2c86d9d2
Example file location C:\Windows\System32\
Filename authui.dll
System Windows 8
File size 2033152 bytes
Date 2012-07-26
File details
MD5 e972817e89a8a216f35cf0fbe30378b8
SHA1 c54516333c0ce016faae0c658714467542d8f459
SHA256 675f53558d30d59ba261935fcbde5d9db49c0273e0b6a0f9eb3973805e821a6c
CRC32 76e68282
Example file location 1: C:\Windows\System32\
Filename authui.dll
System Windows 7
File size 1927680 bytes
Date 2010-11-21
File details
MD5 0bee002c68e28ce6da161dcf1376d7d7
SHA1 d5cc3bec12c801e11217acc6927e1e6e401fe208
SHA256 1d4ee0b9ce22d139478008d5591b8c9f027c235cba601f95a96547cf98159d4b
CRC32 ac8787b4
Example file location C:\Windows\System32\
Filename authui.dll
System Windows 7
File size 1792000 bytes
Date -0001-11-30
File details
MD5 cdd35c1ce1ebfe80c055691cdc8df443
SHA1 f519446aa941655aa28d158bbe78cf51f5402b93
SHA256 de548012a90fffcf6b6ca1ffa5c04167cbaaa8656d7d9a7132d62340c3958409
CRC32 8ba407f7
Example file location C:\Windows\System32\
Filename authui.dll
System Windows Vista
File size 2272256 bytes
Date 2009-04-11
File details
MD5 363d07c0f427c72bde0b6d6492a205c9
SHA1 9e06d12efa0ac52193df0349142f9e131240e7b9
SHA256 539ce7ca6d2542af9d23bfed471c69afa7e78ea054ce3fb54d558426707ee680
CRC32 c4bf2e98
Example file location ---
Filename authui.dll
System Windows Vista
File size 1985024 bytes
Date -0001-11-30
File details
MD5 58c2521d87c494831a625202c80354ad
SHA1 4a8936f342428aafae21b79468e3500bbc6dcfaf
SHA256 6c5d9503e587904f5207e0ab470325dbea0c32eb6693521de669df2d0bd935d4
CRC32 e2d73ee3
Example file location ---