[Solved] System Thread Exception Not Handled in Windows 10/11

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Ever been greeted by a dreaded blue screen that says “System Thread Exception Not Handled”? You’re not alone. This BSOD (Blue Screen of Death) is surprisingly common among Windows 10 and Windows 11 users and often catches people off guard—especially if it happens during boot.

The good news? This error is usually fixable. Most of the time, it’s caused by outdated or faulty drivers—especially GPU or system drivers. In this guide, we’ll walk you step-by-step through what causes this error and how to resolve it using safe, proven methods.

This article is based on real-world cases from Microsoft’s documentation, Reddit threads, and our hands-on experience helping users troubleshoot BSODs.

What Does “System Thread Exception Not Handled” Mean?

When Windows encounters a critical error it can’t recover from, it shows a Blue Screen of Death (BSOD) to prevent further damage. The “System Thread Exception Not Handled” message means a system thread (a key part of Windows) encountered an error it couldn’t manage—and usually, a driver is to blame.

You might also see this error accompanied by a file name like:

  • atikmdag.sys – AMD GPU drivers
  • nvlddmkm.sys – NVIDIA GPU drivers
  • dxgmms2.sys – DirectX graphics
  • igdkmd64.sys – Intel GPU drivers

These file names point directly to the failing driver, helping us diagnose the issue faster.

⚠️ Common Causes:

  • Corrupted or outdated drivers (especially graphics drivers)
  • Faulty RAM or hardware
  • Disk corruption or file system damage
  • Recently installed updates or new hardware

When and Why the Error Occurs

This error usually doesn’t give a warning. It might appear:

  • During system boot-up
  • After a Windows update
  • Randomly while using demanding apps like games or video editors

Real users have reported it after installing new graphics cards or updating display drivers—Reddit threads and Microsoft forums are full of similar stories.

In many cases, graphics drivers (especially for AMD or NVIDIA cards) are the main culprit.

How to Identify the Faulty Driver or Cause

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Before fixing the error, we need to figure out what caused it. Here’s how:

✅ Boot into Safe Mode

If your system crashes constantly, Safe Mode allows you to boot with minimal drivers:

  1. Power off your PC, then turn it back on.
  2. When it starts loading, hold the power button until it shuts off again. Repeat 2-3 times until you enter Windows Recovery Environment (WinRE).
  3. Go to Troubleshoot > Advanced options > Startup Settings > Restart.
  4. Press F4 or F5 to boot into Safe Mode.

✅ Use Event Viewer or BlueScreenView

  • Event Viewer: Check Windows Logs > System for recent error entries around the crash time.
  • BlueScreenView (free tool): Highlights the driver or file responsible for BSODs.
  • WinDbg: More advanced users can analyze .dmp files from C:\Windows\Minidump.

[Step-by-Step Fixes] How to Fix System Thread Exception Not Handled in Windows 10/11

Let’s get into the actual fixes. Try them one by one:

✅ Fix 1: Boot into Safe Mode

As mentioned earlier, Safe Mode is crucial for troubleshooting this error, as it loads only essential drivers and services, allowing you to perform various fixes with minimal interference. It’s often the first step in resolving BSOD issues.

✅ Fix 2: Update or Roll Back Device Drivers

Many System Thread Exception Not Handled errors are caused by outdated or faulty drivers, especially for the GPU (Graphics Processing Unit). To fix this in Safe Mode:

  1. Press Windows + X and select Device Manager.
  2. Expand Display Adapters and locate your GPU.
  3. Right-click on your GPU and select Update Driver to search for the latest version. Alternatively, if a recent update caused the issue, right-click and choose Roll Back Driver (if available).
  4. Repeat these steps for other critical drivers, such as network adapters and storage controllers.

If you’re unsure about the driver, you can uninstall it, and then reboot. Windows will often automatically reinstall a compatible driver on startup.

✅ Fix 3: Run System File Checker (SFC) and DISM

Corrupt system files are another common cause of BSOD errors. Running the System File Checker (SFC) and Deployment Imaging Service and Management Tool (DISM) can help repair these corrupted files.

  1. Open Command Prompt as Administrator. To do this, search for “Command Prompt,” right-click it, and choose Run as Administrator.
  2. Run the following command to scan for and repair corrupted system files: bash sfc /scannow
  3. After SFC completes, run the DISM command to repair any issues with the Windows image: swift DISM /Online /Cleanup-Image /RestoreHealth

These commands work together to fix common system file corruption issues that could be triggering the BSOD error.

✅ Fix 4: Perform a Clean Boot

A Clean Boot helps determine if a third-party application or service is causing the issue. It starts Windows with the minimum set of drivers and startup programs, eliminating potential conflicts.

  1. Press Windows + R, type msconfig, and hit Enter.
  2. In the System Configuration window, go to the Services tab.
  3. Check Hide all Microsoft services and click Disable all.
  4. Then, navigate to the Startup tab and click Open Task Manager.
  5. In Task Manager, disable all startup items by right-clicking each and selecting Disable.
  6. Close Task Manager, then click OK and restart your PC.

If the error no longer appears after a clean boot, gradually re-enable the disabled services and startup items one by one until you identify the culprit.

✅ Fix 5: Reset BIOS/UEFI Settings to Default

Sometimes, a recent BIOS update or hardware change (like new memory or a different graphics card) can cause conflicts that result in the System Thread Exception Not Handled error. Resetting your BIOS/UEFI settings to default can help.

  1. Restart your PC and press the key to enter BIOS/UEFI (commonly F2, Del, or Esc).
  2. Look for an option such as Load Setup Defaults or Reset to Default (this varies by manufacturer).
  3. Select this option, then Save and Exit.

Resetting the BIOS/UEFI settings can resolve issues caused by unstable overclocking, improper settings, or conflicts between hardware and BIOS configurations.

✅ Fix 6: Repair Windows via In-Place Upgrade or System Restore

If none of the previous fixes work, you can use System Restore or perform an In-Place Upgrade to repair your Windows installation while keeping your files.

  1. System Restore:
    • Boot into Safe Mode or Windows Recovery Environment (WinRE) by restarting your PC and pressing F8 or Shift + F8 during boot.
    • Navigate to Troubleshoot > Advanced Options > System Restore and follow the prompts to restore your system to a previous working state.
  2. In-Place Upgrade:
    • If you don’t have a restore point, use the Windows 10/11 installation media to reinstall Windows while keeping your files and apps intact.
    • Boot from the installation media, select Install Now, and choose the option to Upgrade this PC. This will fix system corruption and errors without a full reinstall.

✅ Fix 7 (Optional): Recover Lost Files After System Crash

In some cases, a BSOD can result in lost or corrupted personal files. Before reinstalling Windows, you might want to recover important documents or photos.

You can use WinfrGUI, a free and beginner-friendly tool built on Microsoft’s Windows File Recovery engine. It helps retrieve lost files after system crashes or reinstalls.

  • Download and install WinfrGUI from the official website to begin the file recovery process.
Download WinfrGUI Free
  • Open the program and carefully select the drive or partition where your files were accidentally lost or deleted.
  • Specify the types of files you want to recover—such as documents, photos, or videos—and start a full scan.
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  • Once the scan is complete, preview the recoverable files and choose the ones you wish to restore to a safe location.
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This can be a lifesaver if your documents or media files disappeared after repeated BSODs.

When to Contact a Professional

You might need outside help if:

  • The BSOD persists even after reinstalling Windows
  • You experience screen artifacts, system beeps, or random freezes—signs of failing GPU or RAM
  • Hardware diagnostics return errors

In those cases, contact Microsoft Support, visit a local repair shop, or consult your device manufacturer’s service center.

Real User Experiences and Solutions

Reddit is full of user stories involving this BSOD:

  • One user resolved the issue by rolling back their NVIDIA driver from the latest version to an earlier stable release.
  • Another found that their third-party antivirus was interfering with system files—removing it fixed the crash.
  • A post on Microsoft Answers described a successful fix using System Restore after a failed Windows Update.

These cases show that most people fix the error without reinstalling Windows, often just by tweaking drivers or settings.

Conclusion

The “System Thread Exception Not Handled” error can feel intimidating, but in reality, it’s one of the more manageable BSODs. Whether it’s a rogue driver, system corruption, or a faulty BIOS setting, the solutions above will cover nearly every scenario.

✅ Quick Recap:

  • Boot into Safe Mode
  • Check and update drivers
  • Use tools like SFC and DISM
  • Perform a clean boot
  • Reset BIOS if needed
  • Recover files with WinfrGUI, if anything is lost
  • Repair or restore Windows as a last resort

Remember: keep your drivers up to date, avoid abrupt shutdowns, and back up important data regularly. You’ve got this!

Also Read👉How To Boot Into Recovery Mode Windows 10(5 Fast Ways)

Frequent Asked Questions

Q1: What causes the “System Thread Exception Not Handled” error?
A: This error is usually caused by a faulty or outdated GPU or chipset driver. Other possible causes include corrupted system files, RAM issues, or disk errors. Updating drivers and performing system scans can help fix the issue.

Q2: Can I fix this without reinstalling Windows?
A: Yes! Most users fix this by updating or rolling back drivers (especially for the graphics card), or using Safe Mode for troubleshooting. You can also run SFC and DISM to repair system files.

Q3: Is this error caused by my graphics card?
A: Often, yes. If the error mentions files like atikmdag.sys (AMD) or nvlddmkm.sys (NVIDIA), it’s likely due to your graphics card driver. Updating or rolling back the driver can help.

Q4: Will this BSOD cause permanent damage to my computer?
A: The BSOD itself doesn’t cause permanent damage, but repeated crashes can lead to file corruption or data loss. Fixing the underlying issue and backing up files is important.