Microsoft Windows Error Code 0xC000005F: How to Fix It

Medium 1-2 hours Medium Severity Verified June 2026
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Error Code
0xC000005F
Brand
Microsoft Windows
Product Type
operating_system
Severity
Medium
DIY Difficulty
Medium
Estimated Fix Time
1-2 hours
Error code 0xC000005F, also known as STATUS_BAD_VALIDATION_CLASS, indicates a problem with Windows security validation. This usually happens when a system file or driver is corrupted or incompatible, preventing the OS from verifying its integrity. Don't worry — you can often resolve it with a few straightforward steps.
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Tools You'll Need

How to Fix Error Code 0xC000005F

  1. Restart Your Computer

  2. Run System File Checker (SFC)

    Do not close Command Prompt until the scan completes.

  3. Run DISM Tool

    Ensure you have a stable internet connection as DISM may download files from Windows Update.

  4. Update Windows and Drivers

    Back up important data before major updates.

  5. Perform a Clean Boot

  6. Run Windows Memory Diagnostic

    Save all work before restarting.

  7. Perform System Restore

    System Restore does not affect personal files but may remove recently installed apps.

  8. Reset or Reinstall Windows

    Back up all important data to an external drive before resetting or reinstalling.
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When to Call a Professional

If none of the above steps resolve the error, the issue may be hardware-related (e.g., failing hard drive or memory). Contact a certified technician for hardware diagnostics and repair.

Frequently Asked Questions

What causes Windows error 0xC000005F?
This error usually results from corrupted system files, incompatible drivers, or problematic Windows updates. It indicates that the security validation class is incorrect.
Can error 0xC000005F be fixed without reinstalling Windows?
Yes, in most cases. Running SFC and DISM scans, updating drivers, or performing a System Restore can fix it without a full reinstall.
Is error 0xC000005F dangerous?
No, it's a system error that prevents certain software from running but doesn't damage hardware. However, ignoring it may lead to instability.
Does error 0xC000005F affect my files?
The error itself won't delete files, but some repair steps like resetting Windows may — so always back up your data first.
What if SFC and DISM don't fix the error?
Try a clean boot to rule out third-party software conflicts. If that doesn't work, consider a System Restore or resetting Windows.

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