DRIVER_VERIFIER_IOMANAGER_VIOLATION (0x000000C9): How to Fix This BSOD and Keep Your Drivers in Line

The 0x000000C9 STOP code, also known as DRIVER_VERIFIER_IOMANAGER_VIOLATION, is a Blue Screen of Death (BSOD) error that appears when Driver Verifier detects serious issues with how a driver interacts with the I/O Manager in Windows.

Driver Verifier is a powerful built-in Windows utility designed to expose driver bugs by stressing drivers with extreme scenarios. If a driver fails under these conditions, Windows will crash and show a BSOD like this one — to prevent further damage or data corruption.

What Does This Error Really Mean?

This error means that a driver violated the I/O Manager’s rules — likely by making illegal or out-of-sequence input/output operations. Windows steps in to protect system stability and flags the problem driver.

The exact message on the BSOD might look like:

"DRIVER_VERIFIER_IOMANAGER_VIOLATION"
STOP: 0x000000C9 (Parameters...)

Common Causes of DRIVER_VERIFIER_IOMANAGER_VIOLATION (0x000000C9)

1. Faulty or Incompatible Drivers
   Drivers that do not follow proper I/O request rules can cause this violation, especially under Driver Verifier.
2. Third-party Software Conflicts
   Security programs, low-level utilities, or poorly coded system tools may use custom drivers that break rules.
3. Hardware Failure or Incompatibility
   Defective hardware or misconfigured peripherals can trigger invalid driver behavior.
4. Corrupted System Files
   Damaged Windows system files or registry entries could lead to improper driver loading.
5. Malware or Rootkits
   Malicious drivers or hidden processes can violate I/O rules to gain deeper system access.

How to Fix the 0x000000C9 Error

Step 1: Boot into Safe Mode

1. Hold Shift and click Restart from the Start Menu.
2. Go to Troubleshoot > Advanced Options > Startup Settings > Restart.
3. Choose Safe Mode with Networking.

This disables non-essential drivers so you can troubleshoot safely.

Step 2: Identify the Problematic Driver

If Driver Verifier is active, check the Memory Dump or Event Viewer for logs pointing to the faulty driver:

• Press Win + X > Event Viewer
• Navigate to: Windows Logs > System or Application
• Look for entries near the crash time

You can also use WhoCrashed or BlueScreenView tools to analyze minidumps.

Step 3: Disable Driver Verifier Temporarily

If Driver Verifier keeps crashing your system:

1. Boot into Safe Mode
2. Press Win + R, type verifier, and press Enter
3. Choose Delete existing settings, click Finish, and restart

This will stop Driver Verifier from stressing the system until the issue is fixed.

Step 4: Update or Roll Back Drivers

• Open Device Manager (Win + X > Device Manager)
• Right-click devices with recent updates or flagged symbols
• Select Update Driver or Roll Back Driver

Start with:

• Display Adapters
• Network Adapters
• Storage Controllers
• Custom or third-party device drivers (like printer or gaming hardware)

Step 5: Uninstall Problematic Software

Security software, VPN clients, or system utilities that install kernel-level drivers may be culprits. Uninstall:

• Recently added apps
• System cleaners
• Overclocking tools
• Firewalls or antivirus suites

Then restart and test stability.

Step 6: Perform System File Checks

Run built-in utilities to fix corrupted system files:

bash

CopyEdit

sfc /scannow

‍

And:

bash

CopyEdit

DISM /Online /Cleanup-Image /RestoreHealth

‍

Open Command Prompt as Administrator to run these commands.

Step 7: Check for Windows Updates

Install pending Windows Updates to ensure you're running the latest kernel, security patches, and driver models.

Go to:
Settings > Windows Update > Check for Updates

Step 8: Restore System or Reinstall Windows

If none of the above helps:

• Use System Restore to revert to a clean snapshot
• As a last resort, reset Windows from Settings > Recovery

Back up your files before proceeding.

Tips to Prevent DRIVER_VERIFIER_IOMANAGER_VIOLATION

• Only install drivers from trusted vendors or Windows Update
• Don’t run Driver Verifier unless you're testing driver behavior
• Keep your system firmware and BIOS up to date
• Use Windows Security or reputable antivirus software to keep malware out
• Avoid tweaking system-level I/O settings unless you're experienced

Bonus: How to Use Driver Verifier Safely

Driver Verifier is for developers and advanced users. If you’re debugging or testing drivers:

1. Run verifier from Run dialog
2. Choose “Create standard settings”
3. Select individual drivers or all non-Microsoft drivers
4. Restart the system

Be prepared for BSODs — only use it when needed and always disable it after testing.

Final Thoughts

The 0x000000C9 DRIVER_VERIFIER_IOMANAGER_VIOLATION BSOD is a clear warning: one of your drivers isn’t playing nice with Windows' I/O rules. With careful troubleshooting, safe booting, driver updates, and smart system hygiene, you can resolve this issue and prevent future crashes.

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