KMODE_EXCEPTION_NOT_HANDLED BSOD Fix on Windows 11

For a kmode_exception_not_handled bsod fix on Windows 11, use this order to reduce guesswork: capture the crash clue, test whether Safe Mode is stable, roll back or remove the recent driver if timing points to one, run SFC and DISM if Windows files may be damaged, then test RAM and hardware-related issues if the clue keeps changing or Safe Mode also crashes.

KMODE_EXCEPTION_NOT_HANDLED is bug check 0x0000001E. Officially, it means a kernel-mode program generated an exception that the error handler did not catch. Official guidance also says a faulty device driver or system service can cause it, and hardware issues such as BIOS incompatibilities, memory conflicts, and IRQ conflicts can also generate it. Safe Mode also matters because it starts Windows with a minimal set of drivers and services, which helps separate a normal-boot driver problem from a wider stability problem. (vividrepairs.co.uk)

Start with the strongest crash clue

What to capture before changing anything

The best clue is the file named on the blue screen, then the Event Viewer entry at the crash time, then the newest file in C:\Windows\Minidump. If Windows names a .sys file, treat that as the first lead, not automatic proof, and then check whether Safe Mode changes the behavior.

1. If the blue screen stays visible long enough, write down the exact .sys filename if one appears, and write down the full stop code shown on the screen.
2. If the system reboots too fast, boot to Settings > System > Recovery > Advanced startup > Restart now > Troubleshoot > Advanced options > Startup Settings > Restart, then press 4 for Safe Mode or 5 for Safe Mode with Networking.
3. In Safe Mode, open File Explorer and go to C:\Windows\Minidump. If prompted for permission, select Continue. Switch to Details view and note the newest .dmp file and its timestamp.
4. If the crash started right after a Windows update, GPU driver update, VPN install, RGB utility install, or BIOS change, note that too.

A named driver file can be a useful starting clue, especially before driver rollback or removal. (source)

Which causes are most likely, in order?

Most cases still start with a third-party driver or a software layer attached to one, especially if the first crash followed an update or a new install. After that, check damaged Windows files, then RAM or CPU instability when the blamed file changes between crashes, and then hardware-related issues such as BIOS compatibility or device conflicts. That order matches the official driver-first guidance better than going straight to a full reinstall.

1) Third-party drivers

Check drivers before anything else. Official guidance says a faulty device driver or system service might cause this error, and if a driver is identified in the bug check message, disable the driver or check with the manufacturer for driver updates. Graphics drivers, network drivers, storage controller drivers, virtualization drivers, RGB software, VPN clients, antivirus filter drivers, and anti-cheat tools all fit the pattern because they add code that runs close to the kernel.

2) Corrupted Windows files

After repeated blue screens, Windows files can also need repair, especially after an interrupted update or failed driver install. That moves sfc /scannow and DISM /Online /Cleanup-Image /RestoreHealth higher in the order, but only after the likely driver path has been checked. These are standard Windows repair tools for system files and the component store.

3) RAM or CPU instability

When one crash points to storage, the next to graphics, and the next to networking, the named file may be where the fault surfaced rather than where it started. In practice, that is the point to stop chasing single drivers and start checking unstable memory settings, bad DIMM slots, overclocking, undervolting, or recent firmware changes.

4) Hardware compatibility or device conflicts

If Windows crashes during install, very early boot, or while applying updates, hardware-related issues move up the list. Official guidance specifically includes BIOS incompatibilities, memory conflicts, and IRQ conflicts as possible causes, so early-boot or install-time failures should be checked differently from a crash that only appears after the full desktop loads.

How do I find the .sys file or crash clue?

Look first on the blue screen itself, then in Event Viewer under Windows Logs > System, then in the newest minidump if the screen flashed too quickly. That order is fast and usually enough to separate a likely driver case from a memory or hardware case.

Read the blue screen and minidump

1. At the next crash, note any filename ending in .sys exactly as shown, including the full name such as nvlddmkm.sys or ndis.sys.
2. If no file appears, boot into Safe Mode and open File Explorer > C:\Windows\Minidump.
3. Click View > Details if needed, then click the Date modified column to sort newest first. Save or copy the newest .dmp file to another folder, such as the Desktop or Documents, before making changes.

Check Event Viewer

1. Press Win + X > Event Viewer.
2. Open Windows Logs > System.
3. Select Filter Current Log in the right pane, tick Critical and Error, then set the time range around the exact minute of the crash if you know it.
4. Open each likely entry from that time and look for a driver filename, device name, storage warning, or service failure.

Event Viewer is rarely perfect, but it often narrows the layer. If a driver is named in the bug check message, official guidance is to disable or remove that driver, or check with the manufacturer for updates.

Driver-first fixes when a .sys file, update, or Safe Mode points to a driver

Roll back first when the crash started after an update

1. Right-click Start and open Device Manager.
2. Check Display adapters, Network adapters, and Storage controllers first.
3. Open the suspect device > Properties > Driver.
4. Select Roll Back Driver if available.
5. Restart and test.

Rollback is usually the best first move when the timing is obvious. If Windows Update or a vendor updater ran just before the crashes started, return to the previous known-good driver first.

Update or reinstall when the driver is old, missing, or half-installed

1. In Device Manager, open the suspect device.
2. Select Properties > Driver > Update Driver.
3. If that fails, return to Driver and choose Uninstall device.
4. Restart, then install the vendor driver again.

If rollback is not available, or if the device package is clearly damaged, update or reinstall next. Official guidance says that if a driver is listed by name in the bug check message, disable or remove that driver. OEM-approved graphics, chipset, storage, and network packages are usually the safest first choice on laptops and prebuilt desktops. If the named file points to graphics, start there; if it points to networking, inspect VPNs, NIC drivers, and security software next.

Remove the software layer that sits on top of the driver

1. Open Settings > Apps > Installed apps.
2. Uninstall recent VPN clients, third-party antivirus, RGB suites, peripheral software, or anti-cheat software.
3. Restart into normal mode and retest.
4. If the crash started after enabling Fast Startup, open Control Panel > Power Options > Choose what the power buttons do > Change settings that are currently unavailable, then clear Turn on fast startup.

This step matters because the visible crash may be triggered by software that sits above the base driver. If removing the recent add-on stops the crashes, leave the system stable for several reboots before changing anything else.

What if the BSOD still happens after driver changes?

If rollback, update, removal, or uninstall did not stop the crashes, move to system file repair next. A clear order is to run SFC first, then DISM, with testing after each step.

Run SFC, then DISM

1. Boot into Windows or Safe Mode.
2. Open Command Prompt as administrator.
3. Run sfc /scannow.
4. Restart and test.
5. If crashes continue, open Command Prompt as administrator again.
6. Run DISM /Online /Cleanup-Image /RestoreHealth. (Microsoft Support)
7. Restart and test again.

This is the right stage for both tools, especially after interrupted updates or failed driver installs. Test after each step so it is clear which change helped.

What if it crashes in Safe Mode too?

If the same blue screen still appears in Safe Mode, stop blaming normal startup apps and move down-stack. Because Safe Mode starts Windows with a minimal set of drivers and services, a crash there makes a plain startup app less likely and pushes RAM, BIOS compatibility, device conflicts, or a lower-level driver higher on the list.

Test memory first when the blamed file keeps changing

1. Press Win + R, type mdsched.exe, and press Enter. (Microsoft Learn)
2. Select Restart now and check for problems.
3. After Windows boots, open Event Viewer > Windows Logs > System, then use Find for MemoryDiagnostics-Results to review the result.

Windows Memory Diagnostic is the built-in first RAM check, and it is the first thing to run when the blamed file keeps changing or the crash survives Safe Mode. If the named file changes every crash, do not over-trust any single .sys filename.

Back out unstable tuning and inspect hardware-related install failures

1. Restart the PC and enter BIOS or UEFI Setup by pressing the key shown at startup, commonly Del, F2, or F10.
2. Load default settings using the BIOS option commonly named Load Setup Defaults, Optimized Defaults, or Restore Defaults, then save and exit.
3. Disable XMP or EXPO if enabled, and remove any manual CPU, RAM, or GPU overclock or undervolt settings.
4. If the system crashes during Windows install, recreate the USB installer with Microsoft media on a different USB drive, try a different USB port, and in BIOS check that storage mode matches the system’s expected configuration before testing again.

Hardware-related causes move up the list when the crash happens during installs, updates, or very early boot. If a recent add-in card was installed, remove it temporarily and test with onboard hardware where possible. One reported workaround was replacing a 10G Trendnet network card with the onboard Intel NIC, reported by learn.microsoft.com.

When BIOS or firmware becomes the next suspect

If Safe Mode still crashes after memory checks and default BIOS settings, and the system began failing after a BIOS flash, SSD firmware update, or motherboard setting change, firmware becomes a prime suspect. Enter BIOS/UEFI Setup, load defaults, save, and retest first. If the problem started immediately after a firmware update, install only the PC or motherboard vendor’s recommended BIOS revision and follow the vendor’s standard BIOS update method from its support page rather than using third-party tools or stacking more Windows-side repairs.

KMODE troubleshooting decision table

One-page decision guide

Still not working?

If that did not work, use the next escalation in order

1. Open System Restore and revert to a restore point from before the first blue screen.
2. If Windows boots, mount the current Windows ISO in File Explorer, open the mounted drive, run setup.exe, choose Keep personal files and apps, and complete the in-place repair install before using Reset This PC.
3. Use Settings > System > Recovery > Reset this PC only after driver, corruption, RAM, and hardware checks fail.
4. If the PC still crashes after a reset, run the PC maker’s built-in hardware diagnostics if available, or test by swapping likely parts one at a time such as RAM, the graphics card, or the add-in network card.

For a recurring kmode_exception_not_handled bsod fix windows 11 loop, save the newest minidump, note the exact .sys file, note whether Safe Mode crashes too, and record the last update or hardware change before asking for help. For kmode_exception_not_handled bsod fix windows 11 dell cases, Dell-approved BIOS and driver packages should take priority over generic downloads.

Prevention

Once stable, avoid stacking changes. Do not update BIOS, GPU driver, VPN client, and RGB software on the same day if the machine is already sensitive. Change one layer, test, then move on.

Frequently asked questions

How do I fix KMODE_EXCEPTION_NOT_HANDLED on Windows 11?

Start with the named .sys file or the newest file in C:\Windows\Minidump. If Safe Mode works, use Device Manager > Properties > Driver > Roll Back Driver or Uninstall device on the suspect device. If no driver clue appears, run sfc /scannow, then DISM /Online /Cleanup-Image /RestoreHealth, then test memory.

What driver causes KMODE_EXCEPTION_NOT_HANDLED BSOD?

There is no single guaranteed driver. Official guidance points first to recently changed drivers or system services, so the best answer is the one named by the crash clue and the timing of the failure. Graphics, network, storage-controller, VPN, antivirus, and other filter drivers are common places to check first.

How do I find the .sys file shown on the blue screen?

First read the blue screen itself. If it reboots too fast, boot into Safe Mode, then open Event Viewer > Windows Logs > System and inspect crash-time errors. Also check C:\Windows\Minidump for the newest .dmp file and save it before changing drivers.

Can faulty RAM cause KMODE_EXCEPTION_NOT_HANDLED?

Yes. RAM becomes more likely when the blamed .sys file changes between crashes, the PC also crashes in Safe Mode, or driver rollback does nothing. Run mdsched.exe, review the result in Event Viewer, and if needed test sticks one at a time or in different slots.

Should I update or roll back my graphics driver first?

Roll back first if the blue screens began right after a graphics update or Windows feature update. Update first if the installed driver is old, missing, or partly broken after a failed install. In Device Manager > Display adapters > Properties > Driver, choose the path that matches the timing.

What do I do if the BSOD happens in safe mode too?

Move past normal driver triage and check lower-level causes. Because Safe Mode uses a minimal driver and service set, a crash there points more strongly to memory, BIOS compatibility, device conflicts, or a lower-level driver than to an ordinary startup app. Run Windows Memory Diagnostic, return BIOS tuning to defaults, disable XMP or EXPO, and inspect recent hardware or firmware changes.

Sources

• Microsoft Support documentation for the System File Checker tool and DISM repair workflow. (Microsoft Support)
• Microsoft Learn community discussion referenced for Windows Memory Diagnostic access and follow-up checking. (Microsoft Learn)
• Background page already cited in the article for stop-code context. (vividrepairs.co.uk)
• Related internal reference kept for driver-failure context. (driver install)
• Related internal reference kept for stop-code context. (bsod fix)