Windows BSOD Error 0x00000109 — CRITICAL_STRUCTURE_CORRUPTION Fix

What Does This Error Mean?

The 0x00000109 blue screen means CRITICAL_STRUCTURE_CORRUPTION. Something has modified a part of the Windows kernel it should not have touched. This is usually caused by a faulty driver, bad RAM, or malware.

Affected Models

Windows 10
Windows 11

Common Causes

A kernel-mode driver (often a third-party one) corrupted a critical Windows memory structure
Faulty RAM is writing incorrect data into protected kernel memory
Malware or a rootkit is attempting to modify Windows core components
A recently installed driver or software is incompatible with your Windows version
Hardware failure on the CPU or motherboard is causing unpredictable memory writes

How to Fix It

Scan for malware immediately. Run a full scan with Windows Defender (built into Windows). Then also run a scan with Malwarebytes Free (free download at malwarebytes.com) for a second opinion.

Some rootkits and malware specifically target the Windows kernel. This should be your first step.
Check for recently installed drivers or software. Go to Control Panel > Programs > Programs and Features and sort by install date. Uninstall anything installed just before the crashes started.

A newly installed driver is often the culprit. Rolling it back or uninstalling it is a quick test.
Run System File Checker to repair corrupted Windows files. Open Command Prompt as administrator and type: sfc /scannow — then press Enter and wait for it to finish.

SFC scans all protected Windows files and replaces any that are corrupted. It takes 10 to 20 minutes.
Test your RAM with Windows Memory Diagnostic. Press Windows + R, type mdsched.exe, and press Enter. Select 'Restart now and check for problems.' Let the test run fully.

Bad RAM can cause kernel corruption that triggers this exact blue screen.
Run DISM to repair the Windows component store. Open Command Prompt as administrator and type: DISM /Online /Cleanup-Image /RestoreHealth — then press Enter. This takes several minutes.

DISM repairs the underlying Windows image that SFC uses. Run DISM before SFC for best results.

When to Call a Professional

If this blue screen happens frequently and you have tried all the steps below, take your PC to a technician. A professional can run deep hardware diagnostics to check your RAM, CPU, and motherboard. Malware that causes this error can be very persistent — a professional may be needed to fully remove it.

Frequently Asked Questions

What is the Windows kernel in plain English?

The kernel is the core of the operating system — think of it as the engine of the car. It manages memory, processes, and hardware communication. When something tampers with or corrupts the kernel, Windows stops everything to prevent a worse crash or security breach.

Can a virus cause CRITICAL_STRUCTURE_CORRUPTION?

Yes. Rootkits and advanced malware specifically target the Windows kernel to hide themselves. This is one of the more serious malware scenarios. Run both Windows Defender and Malwarebytes scans. If malware is found and keeps returning, consult a security professional.

Is it safe to keep using a computer that shows this blue screen?

Not regularly. This blue screen indicates a serious instability in your Windows kernel. Your data could be at risk from unexpected crashes. Back up your important files to an external drive immediately and work on fixing the root cause.