How to Fix KMODE_EXCEPTION_NOT_HANDLED (Windows)
Quick Answer
The KMODE_EXCEPTION_NOT_HANDLED error indicates that a kernel-mode program generated an exception that the error handler did not catch. This often points to issues with device drivers, system services, or hardware. A common first step to resolve this is to update or roll back recently installed drivers.
What Causes This Error
- Outdated or corrupted device drivers, especially for network adapters, graphics cards, or storage controllers.
- Conflicting software or recently installed applications that interfere with system processes.
- Corrupted system files or Windows operating system components.
- Hardware malfunctions, including faulty RAM, an overheating CPU, or issues with other peripherals.
- BIOS/UEFI settings that are incorrectly configured or require an update.
- Malware or virus infections that have compromised system integrity.
Step-by-Step Fixes
1Update or Roll Back Device Drivers to Resolve KMODE_EXCEPTION_NOT_HANDLED
- Restart your computer. If the error prevents normal boot, try booting into Safe Mode. To do this, restart your PC, and when you see the Windows logo, press and hold the power button to force shutdown. Repeat this three times to enter the Windows Recovery Environment, then navigate to Troubleshoot > Advanced options > Startup Settings > Restart, and select 'Enable Safe Mode with Networking'.
- Once in Windows (normal or Safe Mode), right-click the Start button and select 'Device Manager'.
- Expand categories such as 'Display adapters', 'Network adapters', and 'Sound, video and game controllers'. Look for any devices with a yellow exclamation mark, which indicates a problem.
- Right-click on a suspicious device (or any device recently updated before the error appeared) and select 'Update driver'. Choose 'Search automatically for updated driver software'. If this does not help, right-click again and select 'Properties', then go to the 'Driver' tab and select 'Roll Back Driver' if the option is available. If not, select 'Uninstall device' and then restart your computer to allow Windows to reinstall a generic driver.
- Repeat this process for other potentially problematic drivers. After making changes, restart your computer to see if the error is resolved.
2Run System File Checker (SFC) and DISM Scans
- Open Command Prompt as an administrator. To do this, type 'cmd' into the Windows search bar, right-click 'Command Prompt' from the search results, and select 'Run as administrator'.
- In the Command Prompt window, type 'sfc /scannow' and press Enter. This command will scan for and attempt to repair corrupted system files. Allow the scan to complete, which may take some time.
- After the SFC scan finishes, type 'DISM /Online /Cleanup-Image /RestoreHealth' and press Enter. This command uses Windows Update to provide files that are needed to fix corruption. This process can also take significant time and requires an active internet connection.
- Once both scans are complete, restart your computer. Check if the KMODE_EXCEPTION_NOT_HANDLED error persists.
3Check for Windows Updates
- Open the 'Settings' application by clicking the Start button and then the gear icon, or by pressing Windows key + I.
- Navigate to 'Update & Security' (or 'Windows Update' on Windows 11).
- Click on 'Check for updates'. Allow Windows to search for and download any available updates.
- If updates are found, install them and restart your computer when prompted. System updates often include driver updates and bug fixes that can resolve stability issues.
4Test RAM for Errors
- Press Windows key + R to open the Run dialog. Type 'mdsched.exe' and press Enter to open the Windows Memory Diagnostic tool.
- Select 'Restart now and check for problems (recommended)'. Your computer will restart and run a memory test.
- Allow the test to complete. This process can take several minutes. If errors are detected, it may indicate faulty RAM modules.
- If errors are found, consider reseating your RAM modules or testing them individually if you have multiple sticks. Replace any faulty modules as necessary.
Advanced Fixes
Perform a Clean Boot
- Press Windows key + R, type 'msconfig' in the Run dialog, and press Enter to open System Configuration.
- Go to the 'Services' tab. Check the box 'Hide all Microsoft services', then click 'Disable all'.
- Go to the 'Startup' tab and click 'Open Task Manager'. In Task Manager, disable all startup items one by one by right-clicking them and selecting 'Disable'.
- Close Task Manager, then click 'OK' in the System Configuration window and restart your computer. This will start Windows with only essential services and startup programs.
- If the error does not occur during a clean boot, enable services and startup items in small groups until the problem reappears to identify the conflicting software.
Update BIOS/UEFI Firmware
- Identify your motherboard model and current BIOS/UEFI version. This information can often be found in System Information (type 'msinfo32' in Run) or by checking your motherboard's manual.
- Visit your motherboard manufacturer's official website. Navigate to the support or downloads section for your specific motherboard model.
- Download the latest stable BIOS/UEFI firmware update file. Carefully follow the manufacturer's instructions for updating the firmware, as this process varies by manufacturer and model and carries a risk if not performed correctly.
- Ensure your computer remains powered throughout the update process. Do not interrupt the update. After the update, restart your system and check for the error.
Frequently Asked Questions
What does KMODE_EXCEPTION_NOT_HANDLED mean?
KMODE_EXCEPTION_NOT_HANDLED is a Windows stop code (Blue Screen of Death) that indicates a kernel-mode program (typically a driver or system service) generated an error that the operating system's error handler could not process. This usually means a critical component has failed unexpectedly.
Can KMODE_EXCEPTION_NOT_HANDLED be caused by hardware?
Yes, hardware issues can frequently cause this error. Faulty RAM, an overheating CPU, or problems with other hardware components like graphics cards or storage drives can lead to kernel-mode exceptions that are not handled by the system.
Is it safe to boot into Safe Mode to fix this error?
Yes, booting into Safe Mode is a standard troubleshooting step. Safe Mode starts Windows with a minimal set of drivers and services, which can help isolate the cause of the error. Many fixes, such as driver updates or system scans, can be performed safely in Safe Mode.
How do I prevent KMODE_EXCEPTION_NOT_HANDLED from happening again?
To prevent this error, regularly update your device drivers and Windows operating system, run antivirus scans, avoid installing unverified software, and monitor your hardware's health and temperatures. If a specific driver or program consistently causes the error, consider replacing or uninstalling it.
What if I can't boot into Windows at all?
If you cannot boot into Windows normally or Safe Mode, you may need to use advanced recovery options. This could involve using a Windows installation media (USB or DVD) to access the Windows Recovery Environment, where you can perform Startup Repair, System Restore, or even a clean installation if other methods fail.