The "SYSTEM_THREAD_EXCEPTION_NOT_HANDLED" BSOD is typically caused by a faulty driver, especially graphics drivers, and can be fixed without reinstalling Windows. 1. Identify the problematic driver from the minidump file using tools like BlueScreenView, noting common culprits such as nvlddmkm.sys for NVIDIA, igdkmd64.sys for Intel, or dxgkrnl.sys for DirectX-related issues. 2. Boot into Safe Mode and use Display Driver Uninstaller (DDU) to completely remove the current GPU driver, then install the latest version from the manufacturer’s website, or update the driver via Device Manager. 3. Ensure Windows and all drivers—especially chipset, storage, and network—are up to date through Windows Update or the PC manufacturer’s support tool. 4. Run memory diagnostics using mdsched.exe to check for RAM issues, execute chkdsk /f /r to scan for disk errors, and run sfc /scannow followed by DISM /Online /Cleanup-Image /RestoreHealth to repair system files. 5. Disable any CPU, GPU, or RAM overclocking settings in BIOS or software, as they can destabilize system threads. 6. Perform a full malware scan using Windows Defender or Malwarebytes to rule out malicious software. 7. If the issue began after a recent change, use System Restore to revert the system or roll back the problematic driver via Device Manager. If these steps fail, perform a clean boot via msconfig to identify software conflicts or proceed with a Windows repair install using the Media Creation Tool, though most cases are resolved by cleanly reinstalling the graphics driver with DDU, confirming that the root cause is usually driver-related and not the operating system itself.

The "SYSTEM_THREAD_EXCEPTION_NOT_HANDLED" Blue Screen of Death (BSOD) in Windows usually points to a problem with a driver or system-level software failing to handle an exception properly. It’s one of the more common BSOD errors and is often fixable without a full system reinstall. Here’s how to troubleshoot and fix it step by step.

1. Identify the Faulty Driver (Check the Minidump)

The error message often includes a file name (e.g., dxgkrnl.sys, nvlddmkm.sys, igdkmd64.sys, etc.). This file is usually the culprit.

• Where to find it:
  The blue screen may briefly show a file name. If not, use Event Viewer or BlueScreenView (a free tool from NirSoft) to read the minidump files located in C:\Windows\Minidump\.

  

• What to do:
  Note the driver name mentioned in the crash dump. Common culprits:

  • nvlddmkm.sys → NVIDIA graphics driver
  • atikmdag.sys or igdkmd64.sys → AMD or Intel graphics driver
  • dxgkrnl.sys → DirectX/Graphics subsystem (often still driver-related)

2. Update or Reinstall Graphics Drivers

Since this error is frequently caused by GPU drivers, start here.

Option A: Safe Mode Clean Driver Reinstall

1. Boot into Safe Mode:

   • Restart your PC and hold Shift while clicking "Restart".
   • Go to Troubleshoot > Advanced Options > Startup Settings > Restart, then press F4 for Safe Mode.

2. Use Display Driver Uninstaller (DDU):

   • Download DDU from Guru3D.
   • Run it in Safe Mode, select GPU > Clean and restart.
   • After reboot, install the latest driver from NVIDIA/AMD/Intel’s official site.

Option B: Update via Device Manager

• Press Win X > Device Manager > expand Display adapters.
• Right-click your GPU > Update driver > Search automatically.
• Or Uninstall device (check "Delete the driver software") and reboot to reinstall.

3. Update Other Drivers and Windows

Outdated or incompatible drivers (especially chipset, storage, or network) can also cause this error.

• Update Windows:

  • Go to Settings > Update & Security > Windows Update and install all pending updates.

• Update drivers:

  • Use Device Manager to check for outdated drivers.
  • Or use your PC/laptop manufacturer’s support site (e.g., Dell SupportAssist, HP Support Assistant) for certified drivers.

4. Run System Diagnostics

Check for Memory Issues

• Press Win R, type mdsched.exe, and press Enter.
• Choose Restart now and check for problems.
• If errors are found, faulty RAM could be the cause.

Check Disk Health

• Open Command Prompt as admin and run:

  chkdsk /f /r

  (You'll need to schedule it for next reboot.)

Scan System Files

• In Command Prompt (Admin), run:

  sfc /scannow

  Then:

  DISM /Online /Cleanup-Image /RestoreHealth

5. Disable Overclocking

If you’ve overclocked your CPU, GPU, or RAM:

• Reset to default settings in BIOS or using the overclocking software.
• Overclocking can destabilize system threads and cause exceptions.

6. Check for Malware

Rare, but possible. Run a full scan:

• Use Windows Defender (Microsoft Defender) or a trusted antivirus.
• Consider a scan with Malwarebytes for second opinion.

7. Roll Back Recent Changes

• Did the issue start after a driver update or software install?

  • Use System Restore to revert to a point before the problem.
  • Search for "Create a restore point" > System Restore.

• Or roll back a driver:

  • In Device Manager, right-click the device > Properties > Driver tab > Roll Back Driver (if available).

Summary: Quick Fix Checklist

• ? Check the BSOD error file (e.g., nvlddmkm.sys)
• ? Boot into Safe Mode
• ? Use DDU to remove and reinstall GPU driver
• ? Update Windows and all drivers
• ? Run sfc /scannow and chkdsk
• ? Test RAM with mdsched.exe
• ? Disable overclocking
• ? Try System Restore if recent change

If the issue persists after all this, consider:

• Testing with a clean boot (via msconfig) to isolate software conflicts.
• Performing a repair install of Windows (in-place upgrade) using the Media Creation Tool.

But in most cases, reinstalling the graphics driver with DDU fixes the "SYSTEM_THREAD_EXCEPTION_NOT_HANDLED" error.

Basically, it's usually a driver issue — especially graphics — and rarely the OS itself.

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