Drivers · critical

How to fix SYSTEM_THREAD_EXCEPTION_NOT_HANDLED (0x7E)

Drivers troubleshooting guide

What this error means

Windows stopped because a system thread, code that runs inside Windows itself, hit an error that nothing caught, most often an invalid memory access. In almost every case the thread belongs to a driver, and the blue screen often names its file after "What failed", for example a graphics, network or storage driver. Microsoft notes that hardware problems such as incompatible devices and memory conflicts can cause it too. It frequently starts after a driver or Windows update and can repeat at every startup.

Updated

Applies to
Windows 11 and Windows 10
Difficulty
Beginner to intermediate
Before changes
Low; System Restore removes apps and drivers installed after the restore point

Reviewed by Matyáš Rada · Documentation checked: 2026-10-31 · Checked against Microsoft's bug check documentation; not tested on every configuration.

Before you begin

Photograph the blue screen, especially the file after "What failed". That file name decides most of the steps below. If Windows cannot start, see the startup guide.

Work through these checks

0 of 7 complete
01Find the driver file on the blue screen

Microsoft's first step is to identify the driver named in the crash and disable or update it.

  1. Look for "What failed: name.sys" on the blue screen photo and search the file name to see which device or program it belongs to.
  2. If the PC restarted too fast, open Event Viewer (Win + R, eventvwr.msc) > Windows Logs > System and check the errors just before the BugCheck event (ID 1001).
What to expect

You know which driver crashed.

If it does not help

Examples: nvlddmkm.sys (NVIDIA graphics), amdkmdag.sys (AMD graphics), igdkmd64.sys (Intel graphics), Netwtw*.sys or rt640x64.sys (network). If no file is shown, continue with step 2.

Browse related errors
02Start in Safe Mode if Windows keeps crashing

Safe Mode loads only basic drivers, so the faulty driver usually does not start.

  1. If Windows still starts, skip to step 3.
  2. Otherwise, force the PC off three times while the Windows logo shows to open the recovery menu.
  3. Choose Troubleshoot > Advanced options > Startup Settings > Restart, then press 4 for Safe Mode or 5 for Safe Mode with Networking.
What to expect

Windows starts in Safe Mode without the crash.

If it does not help

If even Safe Mode crashes, try Troubleshoot > Advanced options > System Restore (step 7).

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03Roll back, update or remove that driver

Replacing the driver that crashed is the fix in most cases.

  1. Open Device Manager (Win + R, devmgmt.msc) and find the device that belongs to the driver.
  2. If the crashes began after a driver update, open Properties > Driver > Roll Back Driver.
  3. Otherwise, install the newest driver from the device or PC maker's website. For graphics drivers, use the installer's clean installation option if it has one.
  4. If the driver belongs to a program (antivirus, VPN, RGB or monitoring tool), uninstall the program and test without it.

Do not use driver updater programs; get drivers from the device or PC maker.

What to expect

Windows runs normally with the replaced or removed driver.

If it does not help

If a program's driver was responsible, install its latest version later and watch whether the crash returns.

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04Update the BIOS and firmware

Microsoft recommends checking the hardware maker for ACPI and other firmware updates for this stop code.

  1. Find your exact PC, laptop or motherboard model on the maker's support page.
  2. Install the latest BIOS/UEFI and, if listed, firmware updates for the SSD and other devices.

Do not switch off the PC during a firmware update.

What to expect

The PC runs current firmware and the crashes stop.

If it does not help

After a BIOS update, check that settings such as the storage mode and memory profile are still correct.

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05Check recently added hardware

Microsoft lists incompatible hardware and memory conflicts as causes.

  1. If you added a device recently, disconnect it and test again.
  2. Check on the maker's website that the device supports your Windows version.
  3. Run the hardware diagnostics from your PC or laptop maker, if available.

Switch off and unplug the PC before removing internal parts.

What to expect

You find out whether a specific device triggers the crash.

If it does not help

If the crash stops without the device, look for a newer driver or firmware for it before using it again.

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06Test the memory and repair system files

Faulty RAM and damaged system files can make a correct driver crash.

  1. Turn off XMP or EXPO memory profiles and any overclock in the BIOS for testing.
  2. Run Windows Memory Diagnostic (Win + R, mdsched.exe) > Restart now and check for problems.
  3. In Terminal (Admin), run DISM /Online /Cleanup-Image /RestoreHealth and then sfc /scannow.
What to expect

The memory test passes and SFC reports no remaining problems.

If it does not help

If the memory test reports errors, follow the memory test errors guide on this site.

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07Undo a recent Windows update or use System Restore

If the crash began right after an update, returning to the previous state is the quickest way back.

  1. In Settings > Windows Update > Update history > Uninstall updates, remove the most recent update.
  2. Or use System Restore (search "Create a restore point" > System Restore, or Troubleshoot > Advanced options in the recovery menu) and pick a point from before the crashes.

System Restore removes apps and drivers installed after the restore point, but not personal files.

What to expect

Windows works again without the stop code.

If it does not help

Pause updates for a week and install them again later, after updating your drivers.

Browse related errors

Possible causes

  • A faulty or incompatible driver, often graphics, network, audio or storage
  • A driver installed or updated shortly before the crashes started
  • Outdated BIOS/UEFI or firmware
  • Newly installed hardware that is not compatible
  • Faulty RAM or other hardware

Useful Windows tools

These commands open Windows tools. Review changes before applying them.

eventvwr.msc
devmgmt.msc
mdsched.exe

Sources & further reading