KMODE_EXCEPTION_NOT_HANDLED: What It Means and How to Fix It

KMODE_EXCEPTION_NOT_HANDLED is a Windows Blue Screen of Death error, logged internally as bug check 0x0000001E. It means a program running in kernel mode — almost always a driver — triggered an exception that Windows’ error handler couldn’t catch, forcing a crash to prevent damage.

The Single Most Useful Thing to Do First

Windows usually names the specific file responsible on the blue screen itself, in the form of a .sys filename. Write it down — that filename tells you exactly which driver to fix, turning this from guesswork into a targeted repair.

If the crash happened too fast to read, check Event Viewer (Windows key + X > Event Viewer > Windows Logs > System) and look for critical errors at the crash time. Common culprits include network adapter drivers, graphics drivers, and third-party antivirus drivers.

Common Causes

• Faulty or outdated drivers — by far the most frequent cause, especially graphics, network, and storage drivers.
• Recently installed hardware or software — if crashes started right after an install, that’s your prime suspect.
• Faulty RAM — memory corruption produces this exact error, and often at random rather than predictable moments.
• Windows Fast Startup — occasionally interferes with a clean reload of drivers at boot.
• Overclocking — unstable CPU or RAM overclocks are a classic source of kernel-mode exceptions.

Step 1: Update or Roll Back the Named Driver

1. Open Device Manager (Windows key + X).
2. Find the device matching the .sys file from the crash.
3. Right-click > Update driver, or download the current version directly from the manufacturer’s site — usually more current than what Windows Update offers.
4. If crashes started right after a driver update, use Properties > Driver > Roll Back Driver instead.

Step 2: Test Your RAM

Search the Start menu for Windows Memory Diagnostic and run it. It restarts your PC and tests memory before Windows loads. If it reports problems and you have multiple RAM sticks, test them one at a time to identify which is failing.

Step 3: Disable Fast Startup

1. Control Panel > Power Options.
2. Click Choose what the power buttons do.
3. Click Change settings that are currently unavailable.
4. Uncheck Turn on fast startup and save.

Step 4: Repair System Files

Open Command Prompt as administrator and run sfc /scannow. If it reports problems it can’t fix, follow with DISM /Online /Cleanup-Image /RestoreHealth, then run sfc again.

Step 5: Undo Recent Changes

If crashes began after a specific change, reverse it: uninstall recently added software (third-party antivirus is a frequent offender), remove newly installed hardware, or reset any overclock to stock speeds. System Restore to a point before the change is the fastest version of this.

If You Can’t Boot Into Windows

Repeated crashes at startup mean you’ll need Safe Mode: interrupt boot three times to trigger the recovery menu, then Troubleshoot > Advanced options > Startup Settings > Safe Mode. From there you can roll back drivers or uninstall the culprit software.

When It’s Hardware

Recurring crashes that survive driver updates, a clean memory test, and system file repair usually indicate genuinely failing hardware — most often RAM, sometimes a storage drive or motherboard fault. At that point, testing components individually or getting the machine looked at is more productive than further software troubleshooting.

FAQ