
This error Unknown Hard Error is usually associated with Windows Server and Windows 10 operating systems. It is an error that is related to the explorer.exe file, sihost.exe file, ctfmon.exe, and other .exe files. It is one frustrating and critical error that can freeze your system and stop any process on your computer system. Some people have complained that whenever this error pops up, they experience problems like a blank screen, frozen taskbar, blank desktop, in summary, they are not allowed to do anything, sometimes briefly while sometimes it takes a long period. Despite all these, this issue can still be fixed if you follow the troubleshooting steps below.
For more related Windows Operating System errors you can read this: How to Fix “Insufficient System Resources Exist to Complete the Requested Service” error, How to fix the issue “The Security Database on the Server does not have a Computer Account for this Workstation Trust Relationship” on Windows Server [Part 2], How to Quickly Fix Windows Search Bar Not Working, Windows Out Of Box Experience: OOBESETTINGSMULTIPLEPAGE error on Windows 10, and Windows cannot connect to the printer: Operation Failed with error 0x000004f8.

The following are some of the causes of this error:
- Explorer.exe, sihost.exe, ctfmon.exe, or other .exe files can cause it.
- A corrupted system file or registry entries in the OS can cause it.
- Malware attack or Virus infection on the system.
- A recent Windows update on the system.
Follow these troubleshooting steps to fix the “Unknown Hard Error”
- Perform a clean boot of the system
Sometimes performing a clean boot of the system will fix this Unknown Hard Error on issue Windows. Just type msconfig
in the Run and hit Enter.
Click on Services and check the box Hide all Microsoft Services and click on Disable all and click Ok.

- Now click on the Startup tab and click on Open Task Manager.
- Select each Startup item and click Disable and Ok when done.
- Reboot the computer.

After completing these few steps, you can confirm the resolution of the issue. You can start enabling the services one after another to detect which service is causing the error. If it’s an installed update you can revert back to the previous state.
- Using CHKDSK command for your Hard drive State
If your hard drive is failing this kind of error can also show. You can use CHKDSK command to remove any of this possible error:
Open your Command Prompt as an administrator and enter the below command
CHKDSK C:
it depends on what letter is attached to your hard drive. This command utility will scan the whole hard drive for errors and try to fix any errors on it.

- Run DISM Command
You can run the DISM (Deployment Image Servicing and Management) command to fix corrupt, damaged, lost files which can lead to this type of “Unknown Hard Error.
Open your Command Prompt as an administrator and enter the below command
DISM.exe /Online /Cleanup-image /Cleanup-image /Restorehealth
I hope you found this blog post on How to Fix “Unknown hard error” on Windows Server and Windows 10 very interesting and helpful. In case you have any questions do not hesitate to ask in the comment section.