Fixes / Windows · Checked

Windows SYSTEM_SERVICE_EXCEPTION: what it means and how to fix it

Short answer

SYSTEM_SERVICE_EXCEPTION (bug check 0x3B) means a program running with full system access, almost always a device driver, crashed while Windows was handling a request. The most likely fix is to find the file shown after "What failed:" on the crash screen (for example nvlddmkm.sys) and then update, roll back or uninstall the driver it belongs to. Graphics, network, webcam and antivirus drivers cause it most often.

What this message means

Windows stopped because code running in the kernel, the most privileged part of the system, hit an error it could not recover from. Microsoft describes bug check 0x3B as an exception that happened while running a routine that moves from ordinary program code to privileged system code. In practice this is usually a driver reading an invalid memory address (exception code 0xC0000005, access violation). Windows restarts to protect your data. If the crash happens once and never again, it may be a one-off. If it keeps happening, something on the PC (a driver, a recent update, security software, corrupted system files or faulty RAM) needs fixing. On Windows 11 version 24H2 and later the same error appears on a black screen instead of a blue one.

Common causes

CauseHow to tell
A faulty, outdated or newly updated device driver (most often graphics, network, Wi-Fi, audio or webcam)The crash screen shows "What failed:" followed by a driver file such as nvlddmkm.sys (NVIDIA), atikmdag.sys or amdkmdag.sys (AMD), igdkmd64.sys (Intel graphics), netio.sys or a Wi-Fi driver, or ks.sys (webcam/streaming). Crashes often happen while gaming, on video calls or when waking from sleep.
Antivirus, anti-cheat, VPN or system-tuning software that installs its own kernel driverThe crashes started after you installed or updated security software, a game anti-cheat (for example vgk.sys for Riot Vanguard), a VPN client or RGB/overclocking utilities. The "What failed" file or the minidump points to that vendor's driver.
A recent Windows update or feature update that clashes with an existing driverThe crashes started within a day or two of an update. Settings > Windows Update > Update history shows a recent quality or feature update, and Reliability Monitor shows the first crash on the same day.
Corrupted Windows system filesThe failing file is a Windows component such as win32kfull.sys, win32kbase.sys or ntoskrnl.exe rather than a vendor driver, and sfc /scannow reports that it found corrupt files.
Faulty or unstable RAM (including XMP/EXPO memory overclocks)Blue screens happen at random with different stop codes and different "What failed" files each time, and Windows Memory Diagnostic or MemTest86 reports errors. It gets worse after you enable XMP/EXPO in the BIOS.
Newly added hardware or a failing storage driveThe crashes began after you added a device (a dock, capture card, USB hub or new drive), or chkdsk and the drive's health tool report bad sectors or errors.

How to fix it

1. Identify the driver that crashed

  1. If the crash screen is still showing, write down the file after "What failed:" (if there is one). That file is your main suspect.
  2. After restarting, open Start, type reliability and open "View reliability history". Click the red X for the crash and choose "View technical details" to see the bug check code and parameters.
  3. Or open Event Viewer and go to Windows Logs > System. Look for Event ID 1001 (source BugCheck) or Event ID 41 (Kernel-Power) logged at the time of the crash.
  4. For a definite answer, install WinDbg from the Microsoft Store, open the newest file in C:\Windows\Minidump, and run !analyze -v. The MODULE_NAME and IMAGE_NAME lines name the driver.
  5. Search the .sys file name to find out which hardware or software it belongs to, then use the fixes below on that driver.

2. Update, roll back or clean-reinstall the suspect driver

  1. Right-click Start and select Device Manager. Check for any device marked with a yellow exclamation point (!).
  2. If the crashes began after a driver update, right-click the device, choose Properties > Driver tab > Roll Back Driver.
  3. Otherwise download the newest driver directly from the manufacturer (NVIDIA, AMD, Intel, or your PC/laptop maker's support page) rather than relying on Device Manager's "Search automatically".
  4. For graphics drivers, choose the installer's clean install option (NVIDIA app or AMD Software: "Factory Reset"), or remove the old driver with Display Driver Uninstaller in Safe Mode first.
  5. Restart and use the PC as normal to see whether the crash comes back.

3. Install Windows updates, or uninstall the update that started it

Windows 11: Settings > Windows Update. Windows 10: Settings > Update & Security > Windows Update.

  1. Open Windows Update (path above) and select Check for updates. Install everything offered, including items under Advanced options > Optional updates (Windows 11) or "View optional updates" (Windows 10), which often include drivers.
  2. Restart the PC.
  3. If the crashes began right after an update, go to Update history > Uninstall updates (Windows 11) or View update history > Uninstall updates (Windows 10) and remove the most recent quality update.
  4. If Windows won't start, uninstall the update from the recovery screen instead: Troubleshoot > Advanced options > Uninstall Updates > Uninstall latest quality update.

4. Remove conflicting security, anti-cheat or tuning software

  1. Open Settings > Apps > Installed apps (Windows 11) or Settings > Apps > Apps & features (Windows 10).
  2. Uninstall third-party antivirus, VPN clients, game anti-cheat and RGB/overclocking or fan-control tools one at a time, starting with whichever was installed or updated most recently. For antivirus, use the vendor's removal tool if it has one. Microsoft Defender switches on automatically.
  3. Disconnect any hardware you added recently (docks, capture cards, USB hubs, extra drives) and restart.
  4. If the crashes stop, reinstall the software from a fresh download or check with the vendor for a fixed version.

5. Repair Windows system files with DISM and SFC

  1. Open Start, type cmd, right-click Command Prompt and choose Run as administrator.
  2. Run: DISM.exe /Online /Cleanup-image /Restorehealth and wait for it to finish.
  3. Then run: sfc /scannow. Keep the window open until verification reaches 100%.
  4. Optionally check the system drive with: chkdsk C: /f, and type Y to schedule the scan at the next restart.
  5. Restart the PC.

6. Test RAM, use Safe Mode or restore Windows

Safe Mode path: Windows 11 Settings > System > Recovery > Advanced startup. Windows 10 Settings > Update & Security > Recovery > Advanced startup.

  1. Press Win + R, type mdsched.exe, press Enter and choose "Restart now and check for problems". Any reported error means a RAM problem. Disable XMP/EXPO in the BIOS, reseat the memory sticks, or test one stick at a time.
  2. If the PC crashes too often to work in, start Safe Mode: select Restart now under Advanced startup (path above), then Troubleshoot > Advanced options > Startup Settings > Restart, then press 4 (or 5 for Safe Mode with Networking).
  3. If Windows won't start at all, turn the PC off during boot twice in a row. The third start opens the recovery environment.
  4. To roll back, choose Troubleshoot > Advanced options > System Restore (or press Win + R and run rstrui.exe) and pick a restore point from before the crashes started.
  5. As a last resort, use Settings > System > Recovery > Reset this PC (Windows 11) or Update & Security > Recovery (Windows 10) and choose Keep my files.

Next time, skip the search

Crade is an AI assistant for Mac and Windows that sees your screen. When a message like this pops up, ask “what does this mean?” and it explains the exact error in front of you, step by step.

Download Crade

Still not fixed?

If the crash continues after a clean driver install, the latest updates and a clean SFC result, collect the files in C:\Windows\Minidump and post them (zipped, via OneDrive or similar) on Microsoft Q&A or a forum such as Ten Forums or Eleven Forum, where volunteers analyse dumps. If the crashes still happen after Reset this PC, or memory or drive tests show errors, the cause is almost certainly hardware. Contact your PC or motherboard maker, or take it to a repair shop, especially while it is under warranty.

Questions people ask

Is SYSTEM_SERVICE_EXCEPTION serious?

A single crash is usually harmless, and your files are not damaged by the restart itself. Repeated crashes point to a driver, software or hardware problem that should be fixed, because each unexpected shutdown risks losing unsaved work.

Can RAM cause SYSTEM_SERVICE_EXCEPTION?

Yes. Faulty or overclocked memory can corrupt data a driver relies on. Suspect RAM when the stop code and the "What failed" file change from crash to crash, and confirm it with Windows Memory Diagnostic (mdsched.exe) or MemTest86.

What does "What failed: nvlddmkm.sys" (or another .sys file) mean?

It names the driver that was running when the crash happened. nvlddmkm.sys is the NVIDIA graphics driver, so a clean reinstall of the latest (or previous stable) NVIDIA driver is the fix to try first.

Why do I get this error while gaming?

Games put heavy load on graphics drivers and often load anti-cheat kernel drivers, the two most common causes of 0x3B. Update or clean-reinstall the GPU driver, remove any GPU overclock, and update or reinstall the game's anti-cheat.

How do I fix it if my PC crashes before Windows loads?

Interrupt startup twice to reach the recovery environment, then use Troubleshoot > Advanced options to boot into Safe Mode, uninstall the latest update or run System Restore. From Safe Mode you can roll back or remove the faulty driver.

Sources

Related errors