KMODE_EXCEPTION_NOT_HANDLED is one of the most common blue screens on Windows 11, and the good news is hidden in the name: “KMODE” means a kernel-mode program — almost always a driver — did something illegal. That makes this one of the more diagnosable stop codes. Unlike CRITICAL_PROCESS_DIED , where Windows just knows something critical vanished, KMODE crashes usually leave a trail pointing at the guilty driver.

It typically strikes right after a GPU, Wi-Fi, or chipset driver update. Start by identifying the driver (Fix 1), then repair or replace it, then rule out the deeper causes.

Why this happens

  • Buggy or outdated driver — A driver with a coding error accesses invalid memory or raises an unhandled exception in kernel mode, the most common cause by far.
  • Conflicting drivers — Two drivers (for example, an old OEM driver and a newer Windows Update driver) fighting over the same device can trigger the crash.
  • Corrupted driver installation — An interrupted install or a partial update leaves a driver in a half-working state.
  • Faulty RAM — Bad memory cells corrupt driver data, making crashes blame a different driver each time.
  • Fast Startup hibernation conflicts — The hybrid-shutdown kernel session can load stale driver state on boot, especially on dual-boot or older-driver systems.
  • Outdated BIOS/firmware — Old firmware can misreport hardware to newer drivers, causing illegal memory access.

How to fix it

Start by identifying the suspect driver (Fix 1), then repair or replace it. Only move to the deeper fixes if the driver work doesn’t help.

Fix 1: Identify the faulty driver from the minidump or Event Viewer

Guessing wastes time. A two-minute check usually names the exact .sys file.

  1. Press Win + R, type %SystemRoot%\Minidump, and press Enter. If the folder doesn’t exist, enable dumps at Settings > System > About > Advanced system settings > Startup and Recovery > Settings, setting “Write debugging information” to Small memory dump.
  2. Note the newest .dmp file. Download WinDbg Preview from the Microsoft Store, open the dump, and run !analyze -v. The MODULE_NAME line — e.g. nvlddmkm.sys (NVIDIA) or rtwlanu.sys (Realtek Wi-Fi) — identifies the driver.
  3. Or open Event Viewer (Win + X), go to Windows Logs > System, and filter Error events from BugCheck around the crash time.
  4. Search the web for the filename to learn which device it belongs to — that tells you which driver to update or remove next.

Fix 2: Update drivers via Device Manager

If the minidump names a specific driver, update it first. Otherwise, update graphics, network, and chipset drivers — that fixes most cases.

  1. Right-click Start and open Device Manager.
  2. Find the matching device — Display adapters for GPU, Network adapters for Wi-Fi/Ethernet, Storage controllers for storage drivers.
  3. Right-click it and choose Update driver > Search automatically for drivers.
  4. For graphics drivers, get the driver directly from NVIDIA , AMD , or Intel instead — their releases are newer and better tested than Windows Update’s.
  5. Restart and use the PC normally before changing anything else, so you know which change worked.

Fix 3: Roll back the recently updated driver

When blue screens started right after a driver update, the new driver is the suspect.

  1. In Device Manager, right-click the device, choose Properties > Driver, and click Roll Back Driver if it’s available.
  2. Restart and test. If crashes stop, block Windows Update from reinstalling the bad version via Settings > Windows Update > Advanced options > Optional updates or Microsoft’s Show or hide updates troubleshooter.
  3. If Roll Back is greyed out, right-click the device and choose Uninstall device (check “Attempt to remove the driver for this device” if offered), then install an older stable version from the manufacturer’s site.

Fix 4: Disable Fast Startup

Fast Startup saves the kernel session to disk at shutdown, which can reload corrupted driver state on every boot. Disabling it forces a clean driver load each time.

  1. Open Control Panel > Hardware and Sound > Power Options > Choose what the power buttons do.
  2. Click Change settings that are currently unavailable, uncheck Turn on fast startup (recommended), and click Save changes.
  3. Shut down fully (not restart — a restart already bypasses Fast Startup), power back on, and use the PC for a day.
  4. If this fixes it, a half-finished update may have left your drivers in the state Fast Startup was tripping over — similar to the mess behind Windows update stuck at 100 percent .

Fix 5: Run Windows Memory Diagnostic

If minidumps keep blaming different drivers, the common denominator is probably RAM, not drivers.

  1. Press Win + R, type mdsched.exe, and press Enter.
  2. Choose Restart now and check for problems. The standard test takes 10–30 minutes; press F1 at the test screen and choose Extended for a thorough check.
  3. Results appear as a notification after Windows boots; you can also find them in Event Viewer > Windows Logs > System, source MemoryDiagnostics-Results.
  4. If errors are found, reseat the RAM modules and test again. Errors that persist mean the module needs replacing — no driver update will fix bad memory.

Fix 6: Update BIOS/firmware

An outdated BIOS can feed wrong hardware information to modern drivers, causing kernel exceptions. Treat this as a fix for persistent cases, not a first step.

  1. Press Win + R, type msinfo32, and note System Manufacturer, System Model, and the current BIOS Version/Date.
  2. On the manufacturer’s support site, check the BIOS section for a version newer than yours — apply it if the release notes mention stability, BSOD, or compatibility fixes.
  3. Run the update with the laptop plugged into AC power and all other programs closed.
  4. Safety note: Do not power off or close the lid during a BIOS flash — an interrupted flash can brick the motherboard. This is the only fix here with that risk, which is why it’s near the end.

Fix 7: Clean driver reinstall with Display Driver Uninstaller (DDU)

When updates and rollbacks don’t help — especially for GPU-related crashes — leftover files and registry entries from old installs can keep the conflict alive.

  1. Download Display Driver Uninstaller (DDU) from Wagnardsoft’s official site.
  2. Boot into Safe Mode (hold Shift, click Restart at the login screen, then Troubleshoot > Advanced options > Startup Settings > Restart, press 4).
  3. In DDU, select your GPU brand and choose Clean and restart.
  4. After rebooting, install only your chosen driver — prefer the Studio/Stable release over the newest Game Ready/beta. Stay offline during the reinstall if Windows Update keeps grabbing a driver first.

If crashes continue after a clean reinstall, try a clean boot (msconfig, disabling non-Microsoft services) — antivirus filters and virtualization drivers are frequent hidden offenders. Crashes on a fresh Windows install point to hardware: run the manufacturer’s boot-time diagnostics or visit a repair shop.

Frequently asked questions

What causes KMODE_EXCEPTION_NOT_HANDLED on Windows 11?
A kernel-mode driver bug: a driver accesses memory it shouldn’t, or throws an exception the kernel can’t catch, and Windows halts with this stop code. The usual culprits are graphics, network, or storage drivers — it often appears right after a driver or Windows update.
How do I know which driver caused the crash?
Check C:\Windows\Minidump for .dmp files from the crash time — BlueScreenView or WinDbg Preview can read them and usually name the faulty .sys file. Alternatively, open Event Viewer, go to Windows Logs > System, and look for Error events from BugCheck around the crash timestamp.
Can faulty RAM cause KMODE_EXCEPTION_NOT_HANDLED?
Yes. Bad memory corrupts the data a driver reads, making a healthy driver look guilty — which is why Fix 5 is the Windows Memory Diagnostic. If successive minidumps blame different drivers, suspect RAM, and run the memory test before replacing drivers repeatedly.
Is KMODE_EXCEPTION_NOT_HANDLED a hardware failure?
Not usually — it’s mostly a software problem: a buggy or incompatible driver, or a corrupted Windows component. Hardware only enters the picture when crashes are random across drivers or persist after a clean reinstall; then RAM and the system drive are the prime suspects.