An Ultimate Guide to Fixing SYSTEM_THREAD_EXCEPTION_NOT_HANDLED

SYSTEM_THREAD_EXCEPTION_NOT_HANDLED is a Blue Screen of Death (BSOD) stop code in Windows indicating a system thread encountered an error that it couldn’t manage. You may encounter it when booting the PC or playing games.

The error is usually due to a corrupt or outdated device driver, corrupted system files, scattered paging file (virtual memory issues), overclocking, faulty CPU, etc.

When this BSOD occurs, try restarting the PC to see if you can boot into Windows. If it doesn’t work, enter WinRE, go to Troubleshoot > Advanced options, and then use the Startup Repair option to solve the issue.

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If the blue screen issue is resolved using the above methods, and it doesn’t occur frequently, no further action is needed. If it occurs frequently or the above methods fail to resolve the issue, use the following repair methods.

Identify the Culprit Behind the Issue

You can use the usual methods to fix the system thread exception not handled Windows 11/10 issue. However, if you can determine what caused the error, you can fix it faster and more accurately.

Sometimes, the stop code system thread exception not handled is followed by a faulty driver file name like WinFsf.sys, GMGHS.sys, nvlddmkm.sys, Ntfs.sys, vgk.sys, etc.

However, in most cases, the faulty file’s name is unknown. You need to analyze the dump file of the system to identify it.

A system dump file is located in C:\Windows\Minidump. It is a snapshot of the system’s memory and state, captured when the system crashes, freezes, or encounters an error.

#1. Enter Safe Mode

When your PC won’t boot into Windows, you need to enter Safe Mode to perform the following solutions or access the dump file.

Here is how to enter Safe Mode.

1. Enter WinRE by interrupting boot three times.
2. Go to Troubleshoot > Advanced options > Startup Settings.
3. Click Restart.
4. Press F5 to enable Safe Mode with Networking.

#2. Analyze the Dump File

Here is a brief guide on how to analyze the dump file.

Step 1: Open the dump file with a debugger tool.

1. Go to C:\Windows\Minidump and then copy the DMP file to the desktop.
2. Download and install the WinDbg tool from the Microsoft Store.
3. Open this tool and click File > Start debugging > Open dump file.
4. On the right panel, click Browse and select the DMP file.
5. Click Open.

Step 2: Identify the culprit file.

1. After the dump file loading is complete, in the text bar, type “!analyze -v” and press Enter.
2. Wait for it to give you the Bugcheck Analysis.
3. Under Debugging Details, see the WARNING information. It will tell you the culprit file of the BSOD system thread exception not handled.

Solution 1. Disconnect Peripherals

Some users report that the USB WiFi, USB headset, or some other peripherals may interfere with the PC booting, causing the system thread exception not handled Windows 10/11 issue.

Pull out these peripherals, including the keyboard and mouse, restart the PC, and then check if the blue screen disappears.

If the problem is indeed related to these peripherals, you need to connect one external device at a time and then start the computer. In this way, you can determine which specific external device is causing the problem.

Then, update the driver of the device. If necessary, replace the device.

Solution 2. Rename the Driver File

If the stop code system thread exception not handled has been followed by the faulty driver file’s name, you can try this method when you can’t enter Safe Mode.

Step 1: Open Command Prompt in WinRE.

1. Enter WinRE and go to Troubleshoot > Advanced options > Command Prompt.
2. Choose your account to continue.
3. Enter your password and click Continue.

Step 2: Once Command Prompt opens, use DiskPart commands to identify your OS drive as drive letters may differ in WinRE.

1. Type “DiskPart” and press Enter. You should now get DISKPART> appear.
2. Type “List volume” and press Enter. A list of your drives should now appear. Identify the drive letter that is your OS drive.
3. Type “Exit” and press Enter. It will take you out of DiskPart.

Step 3: Rename the failed driver file so Windows can’t call it on boot, but it won’t delete it.

1. Type your OS drive letter (D: for example) and press Enter.
2. Type “cd \windows\system32\drivers” and press Enter. This will navigate into the driver folder.
3. Type “ren driver_file another-name” and press Enter. Taking nvlddmkm.sys as an example, the command could be “ren nvlddmkm.sys nvlddmkm.bak”.

Step 4: Close the Command Prompt and shut down your PC. Then, reboot your PC and check if the issue has been solved. Once in Windows, you need to update the failed driver or uninstall the conflicting software.

Solution 3. Place the Page File in a Single Partition

If the stop code SYSTEM_THREAD_EXCEPTION_NOT_HANDLED indicates a problem with memory management, it may not be caused by the memory stick, but the scattered page file.

A paging file (pagefile.sys) is a hidden file on your hard drive. It is used by Windows to serve as virtual memory, an overflow for your physical RAM.

By default, the paging file is not distributed but is located only on the C drive. However, you can still check that in the following steps.

1. Type “view advanced system settings” in the Windows Search bar and select it from the results.
2. In the pop-up System Properties window, on the Advanced tab, under Performance, click Settings.
3. In the Performance Options window, go to the Advanced tab.
4. Under Virtual memory, click Change.
5. Uncheck the box for Automatically manage paging file size for all drives.
6. Select partitions except for C: and make sure No paging file is set for them (click the Set button for each of the partitions).
7. Make sure the C: drive has selected the System managed size option.
8. Then, click OK to save the changes.

Solution 4. Disable Overclocking

Overclocking may result in an unstable computer, which may be the reason for the BSOD system thread exception not handled.

Then, try disabling overclocking to see if the issue can be solved. To do that, reset the BIOS. Here is the guide:

1. Power on the computer and then press the BIOS key (F2, Del, Esc, etc.) once the PC logo appears. This will lead you to the firmware.
2. Navigate to the Exit or System Configuration tab, and find Load Setup Defaults, Restore Defaults, or Load Optimized Defaults.
3. Select this option and confirm.
4. Press F10 to save changes and exit the firmware.

Solution 5. Repair System Files

If the failed file is a Windows system file, repairing the system files may solve the system thread exception not handled Windows 11/10 issue. Here is the guide:

1. In the Windows Search bar, type “cmd”.
2. From the result list, right-click Command Prompt and choose Run as administrator.
3. Type “dism.exe /online /cleanup-image /restorehealth” and press Enter.
4. Once the DISM repair is complete successfully, type “sfc /scannow” and press Enter.

Solution 6. Update Drivers

In most cases, the system thread exception not handled Windows 10/11 is caused by a device driver (especially the keyboard, mouse, and the dedicated GPU device drivers). The driver may be corrupt or outdated, so it can’t go through the computer booting process.

In this case, you can solve the issue by updating the device driver. Here is the guide:

1. Press the Windows logo key + X and then select Device Manager to open it.
2. Expand the device directory corresponding to the problematic driver (Display adapters, Keyboards, Mice and other pointing devices, and so on).
3. Right-click the device and choose Update driver.
4. Select Search automatically for drivers.

Solution 7. Uninstall Programs

Installing programs, especially those hardware-related ones, may add new drivers or replace existing ones. If the driver required by the software is corrupt, the system thread exception not handled Windows 10/11 may occur. Then, uninstalling the software can solve the issue.

The driver required by the software may be corrupted by a Windows update or another program that calls the same hardware. Here are two specific examples.

#1. Windows updates broke the driver.

A user reports that the system thread exception not handled issue occurs after a Windows update. The dump file indicates that it’s caused by a virtual driver associated with the Vanguard anti-cheat software. It’s speculated that the update broke the driver.

#2. Another program broke the driver.

A user reports that he has a Logitech m650 with the Logitech Options+ application running. But he also has X mouse button control. Since he installed the Logitech app, the X mouse hasn’t worked. The Logitech app likely corrupted the driver required by the X mouse.

Finally, he solved the BSOD system thread exception not handled issue by uninstalling the X mouse.

Solution 8. Perform System Restore

System Restore is a feature in WinRE. It can revert your PC’s system files, registry, settings, and apps to an earlier point in time, called a “restore point.” This can fix problems like system crashes, driver conflicts, or software issues without affecting your personal documents, photos, or other data.

If you have enabled the system protection feature, Windows will automatically create restore points before significant events like updates or installations. Or, you can create them manually.

Here is how to perform a system restore.

1. In WinRE, go to Troubleshoot > Advanced options > System Restore.
2. Select your account, type the password, and click Continue.
3. Click Next, select a restore point, and then click Next again.
4. Confirm your restore point. It will tell you which drives are affected. Then, click Finish.

Solution 9. Reinstall Windows

If all the above methods don’t work, you can try reinstalling Windows. Before that, you need to move your important files out of the unbootable computer.

#1. Recover Data

If your computer can boot into Safe Mode, you can simply move the files to an external drive via copy and paste. However, if you can’t boot into Safe Mode, MiniTool Partition Wizard can help you recover data from the unbootable PC to an external drive.

Here is the guide.

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Step 1: Launch MiniTool Partition Wizard on a well-running PC. Insert a USB drive into this PC. Click Bootable Media.

Step 2: Click WinPE-based media with MiniTool plug-in. When it asks you to choose the media destination, click USB Flash Disk. Read the Note message and click Yes to start the creation process.

Step 3: After the process is complete, click Finish. Then, insert the bootable USB drive into the unbootable PC and make the PC boot from the USB drive. At the same time, connect an external drive to the computer.

Step 4: Once MiniTool Partition Wizard opens, click Data Recovery > Devices. Then, hover over the system disk and click Scan.

Step 5: Wait for a few minutes and then stop the scanning process. Expand Lost Files > Existing Partition. Navigate to the files that you want to recover, just like in Windows. Check the boxes before them and then click Save. In the pop-up window, select the external drive to save recovered files.

#2. Reinstall the OS

After recovering important files, it’s time to reinstall the OS. Here is a guide.

Step 1: Create a Windows installation USB drive.

1. On a normal PC, download the Windows Media Creation Tool (MediaCreationTool.exe) from Microsoft’s website.
2. Insert a USB drive into the PC and run this tool.
3. Accept the license terms.
4. Uncheck the box for Use the recommended options for this PC.
5. Change the Language and Edition to make sure they are suitable for the unbootable PC. Then, click Next.
6. Select the USB flash drive option and click Next.
7. Select the drive letter of the connected USB drive and click Next.
8. Wait until the Windows installation USB drive creation process is complete.

Step 2: Reinstall Windows.

1. Install the Windows installation USB drive into the unbootable PC and then boot the PC from it.
2. Once the Windows Setup interface appears, select language settings, and then click Next.
3. Select keyboard settings and click Next.
4. Select setup option (choose the Install Windows option), check the box before I agree everything will be deleted including files, apps, and settings, and then click Next.
5. Click I don’t have a product key.
6. Select the Windows image version and click Next. Then, it will install Windows on the PC. Wait until the process is completed.

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Solution 10. Run RAM Test

The system thread exception not handled blue screen can also be caused by memory issues. If your computer has two or more memory sticks installed, remove them one by one to check if the issue is caused by one of them.

If your computer has only one memory stick, run a RAM test to check if the memory stick malfunctions. Here is the guide:

1. Press the Windows logo key + R to open Run.
2. Type “mdsched.exe” and press Enter.
3. Click Restart now and check for problems (recommended).
4. Wait for the computer to restart and run the test.
5. Pay attention to the Status information. It will tell you if there are memory problems.
6. Depending on the error message, repair or replace the RAM.

Solution 11. Replace the CPU

In the worst-case scenario, the system thread exception not handled problem is caused by a faulty CPU. In this case, you need to replace the CPU or the computer.

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Bottom Line

This post tells you why the system thread exception not handled BSOD occurs and offers 11 solutions to it. Each solution is explained in detail with listed steps and visual pictures.

When dealing with this issue, if you need to reinstall Windows, recover data before that. MiniTool Partition Wizard can help you do that. If you encounter issues when using it, send an email to our support team at [email protected].