[FIXED] ‘Unknown Hard Error’ On Windows 10

Summary: The Unknown Hard Error may occur due to corrupt system files and various other reasons. This blog outlines the possible reasons behind the error and some effective methods to fix it. 

While trying to boot into Windows 10, I ended up with explorer.exe – System Warning dialog with an “Unknown Hard Error” message. Can anyone help?

Microsoft user

On starting my PC, I am getting ctfmon.exe success unknown hard error. The moment the error appears, my system screen just goes all black. I need solutions for this. Please help!

-Microsoft user

Several Windows 10 users on various forums reported encountering Unknown Hard Error while booting the system, after Windows updates, or opening some applications. Due to this error, they experienced issues, such as blue/black screen, screen flashing, explorer.exe crashing, taskbar froze, etc. There are various reasons that may lead to such an error.

Common Causes behind Unknown Hard Error on Windows 10

Following are some common reasons behind the Unknown Hard Error on Windows 10:

  • Corrupt or missing explorer.exe, sihost.exe, or ctfmon.exe files
  • Problematic Windows updates
  • Hard Drive issues
  • Problem with hardware
  • Corrupted system files or registry entries
  • Malware or virus infection

Methods to Resolve Unknown Hard Error on Windows 10

Below we have mentioned some effective solutions to fix Unknown Hard Error on Windows 10:

Method 1: Perform a Clean Boot on Window 10

If any specific application or software is causing the error, you can try performing a clean boot. For doing so, follow the below-given steps:

  • Click Windows + R and type msconfig in the search box to open System Configurations.
  • Go to Services and select Hide all Microsoft Services > Disable All > OK.
  • Navigate to Startup Tab and click on Open Task Manager.
  • Under Startup in Task Manager, select the programs that have high startup impact, and click Disable.
    Unknown Hard Error
  • Now, exit Task Manager.
  • On the Startup tab, click OK.
  • On restarting the system, it will be in a clean boot environment. Further, try to uninstall or install the corrupt program/app.
  • Lastly, reboot your PC and check if it’s working fine without any issue.

Method 2: Run DISM Command

You can run the DISM (Deployment Image Servicing and Management) command to fix corrupt or damaged files, if they have caused the error. To run DISM command, follow the below-given steps:

  • Simultaneously press Windows + X keys to open the Command Prompt.
  • Select Run as administrator option.
  • Enter the following command in the Command Prompt window. Then, press the Enter key.
    DISM.exe /Online /Cleanup-image /Scanhealth \
    DISM.exe /Online /Cleanup-image /Restorehealth

Method 3: Uninstall Problematic Windows Update

If the Unknown Hard Error occurred after installing Windows 10 updates, then you can uninstall the problematic updates to resolve the issue. Here are the steps:

  • Go to Settings > Update & Security > View update history.
  • From the View update history page, click on Uninstall Updates.
  • Select the recently installed update and click on Uninstall, followed by Yes.
  • Reboot your system and check if the error is fixed.

Method 4: Run SFC/Scannow

System File Checker (SFC), a Microsoft Windows’ built-in troubleshooting utility, can help fix the corrupt system files. To run the SFC tool, follow the below-given steps:

  • Open Command Prompt and select Run as administrator.
  • In the open window, type sfc/scannow and press the Enter key.

Method 5: Perform System Restore

You can also try performing System Restore to fix this error. On detecting any system change, it creates checkpoints automatically. If the Unknown Hard Error occurs due to any system change, you can resolve it using the below-given steps:

  • In the Windows search box, type Create a restore point and open it.
  • Navigate to System Protection and click on System Restore, followed by OK.
  • Now, reboot your PC and check if the error is fixed.

You can also read, How to Recover data from hard drive?

What to do in case of Data Loss?

Sometimes, due to the Unknown Hard Error, you may lose access to your data stored on the system. In such a situation, you must look for reliable data recovery software to recover your data. Stellar Windows Data Recovery Software is one such tool that can recover all kinds of files, folders, photos, documents, emails, and more. It can recover data from formatted and corrupted drives, and also from non-bootable or crashed Windows systems.

How to Recover Lost Data with Stellar Windows Data Recovery Software?

Download and install the Stellar Windows Data Recovery software. Launch it and then proceed with the below-given steps:


Step 1: Select file type

Select the type of data that you want to recover and click on Next.

Step 2: Select recover from

Choose the folder location or drive volume and click on Scan.


Step 3: Scan and recover

When the scan completes, select the files that you wish to recover and click on Recover.

Closing Thoughts

The Unknown Hard Error may lead to system malfunction or even crash. This can put your system and data at great risk. However, you can fix this error by following the methods mentioned in this post. If you end up losing your data because of this error, try using Stellar Windows Data Recovery Software. It helps you recover all kinds of data from Windows PCs and other storage devices. You can download the software’s trial version to evaluate its functionality.

Leave a Reply

Your email address will not be published. Required fields are marked *