How To Fix ‘System Thread Exception Not Handled’ Error?

Pressing the power button on a laptop or PC usually means the device will power up and load. At least, that is what we hope! However, some Windows 10 users might face “System Thread Exception Not Handled” error and a dreaded blue screen of death instead.

System Thread Exception Not Handled Error

This might happen with those who don’t know what a device driver is or how to update them. It might take 10 to 15 seconds to see the blue screen of death after startup or it might show right away, depending on the error that is causing it.

The error code ‘system_thread _exception_not_handled’ typically occurs when you first boot the machine up.

Your PC might get stuck in a reboot loop, which means it can’t be used at all.

Let’s take a look at what exactly this error code is, when and why it happens, and some ways to fix it.

What “System Thread Exception Not Handled” Error Code Means?

Seeing the ‘system_thread _exception_not_handled’ error code means a system thread in your device generated an exception for an error which the handler could not catch.

Because it did not catch and fix the error, a blue screen of death occurred. This made the PC attempt to get information about the error.

You might see the numbers 0x0000007E, 0x1000007E accompanying the stop code.

Hopefully it will show the file name which causes the error, for example bcmwl63a.sys, nvlddmkm.sys, igdkmd64.sys etc so you know exactly why it happened.

System Thread Exception Not Handled Error - nvlddmkm.sys
System Thread Exception Not Handled Error – nvlddmkm.sys

The problem with such an error is your PC is nearly always going to end up in a reboot cycle, forcing you to use safe mode to get out of it.

Why and When Might This Error Occur?

You will mainly see the ‘system_thread _exception_not_handled’ error code when booting up the PC from shutdown or restarting it.

It can happen at other times though, sometimes when you run a program which needs specific graphics drivers in order to work.

If the PC has drivers installed, usually graphic drivers, which are incompatible, wrong, corrupted or outdated, you might get the error.

Malware is another culprit because it can manipulate graphic drivers.

Another reason can be incorrectly installed drivers on Windows 10.

What’s the File Name Attached To the Error Code?

It is helpful to know which graphic driver is causing the error, so seeing a file name attached to the ‘system_thread _exception_not_handled’ error code is useful.

Repairing or updating the graphic driver should solve the problem.

Here are some common file names you might see attached to the error code:

  • Atikmdag.sys: this ATI Radeon Family graphic driver concerns the ATI video card. If you are using an AMD installed graphics card with your device, the drivers for the card are either installed wrong or out of date.
  • Dxgmms2.sys: this is related to installed DirectX drivers.
  • Nvlddmkm.sys: this Nvidia Windows kernel driver is behind this graphic card. Your Nvidia powered graphics card has wrongly installed or out of date drivers.
  • Ntfs.sys: this concerns the Windows NT Server.
  • CMUDA.sys: this one is the driver related to USB device audio.
  • Bcmwl63a.sys: This adaptor is for Broadcom 802.11 and needs a Broadcom Corporation wireless driver. You will see the ‘system_thread _exception_not_handled’ error code if it is outdated or not installed properly.

Any of these errors means you should either uninstall and then reinstall the driver in question, or update it.

If there is a system file attached to the error code not listed above, you need to search it online to find out which driver is the problem.

If you see the error code without an attached file, you should update all your computer’s major drivers. This includes LAN, network, sound and audio, and display (graphic) as well as wireless drivers.

How Do You Boot In Safe Mode On Windows 10?

This error is very similar to “Video Scheduler Internal Error” so if you are stuck in a blue screen of death reboot loop, you will need to boot up in safe mode.

Because you probably can’t access your settings, it is best to boot into Windows Recovery Environment (WinRE) before booting up with safe mode.

System Thread Exception Not Handled Error - Windows Recovery Environment
  1. Hold the power button in for a minimum of 10 seconds (until the PC powers off)
  2. Release the power button then press it back to switch the machine back on.
  3. When you see the Windows logo or another sign the PC has started, hold the power button for another 10 seconds to turn it back off.
  4. Release the power button and press it again to boot the machine back up.
  5. Keep doing this until your computer restarts fully in WinRE.
  6. Click ‘troubleshoot’ from the list that appears in WinRE.
  7. After that click ‘advanced settings’ then ‘startup settings’ and ‘restart’.
  8. Once the PC has restarted, press F5 to get Safe Mode with Networking.


Now let’s take a look at five simple ways to fix “System Thread Exception Not Handled” error:


There are different ways to do this, but the simplest one is to check the system log that is tracking events.

In order to do this, you must open the event viewer:

System Thread Exception Not Handled Error - windows event viewer fix
Windows Event Viewer
  • Press the Windows key + R to open the ‘run’ dialogue box and type in this: “eventvwr
  • Navigate to ‘Windows Logs’ and click to drop the menu down.
  • Now click ‘system’ to see all recent events.
  • Look at the ‘system_thread _exception_not_handled’ error to find out which driver is causing it.


The simplest method of fixing incompatible drivers is to either update them, roll them back to their previous versions, or reinstalling them (if you are already using the most recent driver version).

  • Open your device manager by pressing the Windows key + X, or by typing ‘device manager’ into the search bar.
  • Go through all your drivers, right-clicking every piece of hardware that has a driver, and updating it (you should do all your drivers, including disk drives, network adapters, audio devices, sound devices, and display adapters)
  • When clicking ‘update driver’ you can do an automatic search for the newest version of that driver.
  • To roll drivers back, go through the list of devices again and right-click everything with a driver.
  • Click on ‘properties’ and go to ‘driver’ then click ‘roll back’ and confirm.

If you want to reinstall a driver, you need to uninstall the device first of all, and then go to the manufacturer’s website, locate your device and download the newest driver you see. Then install it manually.


If your ‘system_thread _exception_not_handled’ error is attached to a file name, you can always rename the driver (windows will then get a new copy and reinstall it).

You have to know which hard drive the driver is on first of all:

  • Open the command prompt by typing ‘cmd’ in the search bar, or searching for ‘command prompt’.
  • Type this into the box:
cd windows\system32\drivers

(change this filename to the problematic driver file attached to the error code).

  • Type ‘exit’ and restart the PC.


Corrupted system files can affect your machine’s device drivers.

If you think this is the case, it is possible to run Windows repair programs SFC and DISM to fix them.

  • Open the command prompt as an administrator to run SFC. In Safe Mode, this is located under the ‘advanced options’ in the list.
  • Now type in ‘sfc/scannow’ and press “Enter“.
  • Your PC should now replace any lost, altered or damaged system files.

If you still experience the error afterwards, you can run DISM to restore your computer’s health:

  • Open your command prompt as an administrator then type in these, one by one:
Exe /Online /Cleanup-image /Scanhealth
Exe /Online /Cleanup-image /Restorehealth


If you have backups of your PC, you are able to restore it to an earlier version, before the ‘system_thread _exception_not_handled’ error occurred.

You will need either a recovery drive or a Windows system repair disc to do so:

  • Insert the system repair disc and click on your preferred language.
  • Click ‘repair’ than click ‘troubleshoot’ and ‘advanced options’.
  • After that click ‘system restore’.
  • Follow the directions on the screen.


Although uninstalling and reinstalling or updating drivers usually solves the ‘system_thread _exception_not_handled’ error code, it is possible to still get it even after trying all the above fixes.

If you have been unlucky, you might need to cleanly reinstall the operating system.

Completely wiping then reinstalling Windows 10 will bring the PC back to factory settings.

You will then need to update Windows as well as the basic drivers, so you have the newest versions of everything running.