How to fix stop code 0x1000007E (SYSTEM_THREAD_EXCEPTION_NOT_HANDLED)

Applies to: Windows 11, Windows 10 and older versions. On newer screens you may only see SYSTEM_THREAD_EXCEPTION_NOT_HANDLED with a file name under What failed; older screens and crash logs show STOP: 0x1000007E followed by four parameters.

What stop code 0x1000007E means

0x1000007E and 0x7E are the same bug check. Microsoft lists 0x1000007E as the “_M” version of SYSTEM_THREAD_EXCEPTION_NOT_HANDLED; the difference only matters to developers reading the dump. In plain terms, code running in the Windows kernel hit an exception, often an attempt to read memory it shouldn’t touch, and Windows stopped the PC to protect your data.

The first parameter in the stop message is the exception code. 0xC0000005 means an access violation, the most common case, and usually points at a faulty or incompatible driver. The usual suspects are graphics, network, audio, storage and antivirus drivers, especially just after a Windows update or a new driver install.

Find the file that caused the crash

Check the blue screen for a line such as What failed: atikmdag.sys. That file name tells you which driver to deal with:

• nvlddmkm.sys: NVIDIA graphics driver
• atikmdag.sys or amdkmdag.sys: AMD graphics driver
• igdkmd64.sys: Intel graphics driver
• Netwtw*.sys or rt640x64.sys: Intel Wi-Fi or Realtek network drivers

If you missed it, open Event Viewer, go to Windows Logs > System and look for an error from the source BugCheck around the time of the crash. Windows also saves small crash dumps in C:\Windows\Minidump. You can open them with Microsoft’s free WinDbg app from the Microsoft Store and run !analyze -v; the MODULE_NAME and IMAGE_NAME lines name the likely driver.

Start in Safe Mode if Windows keeps crashing

If the PC crashes before you can do anything, use Safe Mode, which loads only basic drivers:

1. Hold Shift and select Power > Restart on the sign-in screen. If Windows doesn’t load at all, it should open the recovery screen by itself after two or three failed starts.
2. Select Troubleshoot > Advanced options > Startup Settings > Restart.
3. Press 4 for Safe Mode, or 5 for Safe Mode with Networking if you need to download a driver.

If the PC is encrypted with BitLocker, you may be asked for the recovery key on the way. Have it ready from your Microsoft account before you start.

Fix 1: Roll back or update the driver

1. Right-click Start and select Device Manager.
2. Find the device that matches the file name, for example under Display adapters or Network adapters.
3. Right-click it, select Properties, open the Driver tab and choose Roll Back Driver if the crashes started after a driver update.
4. If roll back is greyed out, download the latest driver from the PC maker or the chip maker (NVIDIA, AMD, Intel, Realtek) and install it. For graphics drivers, a clean install option, where the installer offers one, removes leftovers from the old version.

If Windows Update keeps reinstalling the bad graphics driver, see how to stop Windows 11 from updating the graphics driver.

Fix 2: Undo recent updates and software

If the crashes began after a Windows update, open Settings > Windows Update > Update history > Uninstall updates and remove the most recent one. In Windows 10, the path is Settings > Update & Security > Windows Update > View update history > Uninstall updates. Also uninstall anything you added just before the problem started, especially antivirus, VPN, overclocking, RGB lighting and virtual drive tools, since these install kernel drivers too. System Restore, under Troubleshoot > Advanced options > System Restore in the recovery screen, can take the PC back to a point before the change.

Fix 3: Repair system files and check the disk

Open Command Prompt as administrator and run:

DISM /Online /Cleanup-Image /RestoreHealth
sfc /scannow
chkdsk C: /scan

DISM repairs the files that SFC uses as its source, so run it first. For what SFC’s results mean, see how to use sfc /scannow. If CHKDSK reports problems, run chkdsk C: /f and restart to let it fix them.

Fix 4: Test the memory and update the BIOS

When the crash names a different driver each time, or no driver at all, suspect hardware. Press Win + R, type mdsched.exe and choose Restart now and check for problems. If the memory test finds errors, reseat or replace the RAM. Turn off any CPU, memory (XMP or EXPO) or graphics overclock to test at stock speeds.

Also check the PC or motherboard maker’s support page for a BIOS or firmware update, and install chipset drivers from the same page. Follow the maker’s instructions exactly and don’t turn the PC off during a BIOS update.

For other blue screens with similar fixes, see Your PC ran into a problem and needs to restart and DPC Watchdog Violation.

Related guides

• Your PC ran into a problem and needs to restart: how to fix it
• DPC Watchdog Violation on Windows 11 and 10: how to fix it
• Critical Process Died on Windows 10 and 11: how to fix it
• How to use sfc /scannow
• How to stop Windows 11 updating the graphics driver

Official sources:

• Microsoft Learn: Bug check 0x1000007E SYSTEM_THREAD_EXCEPTION_NOT_HANDLED_M
• Microsoft Learn: Bug check 0x7E SYSTEM_THREAD_EXCEPTION_NOT_HANDLED
• Microsoft Learn: Advanced troubleshooting for stop or blue screen errors

Frequently asked questions

Is 0x1000007E a hardware or software problem?

Usually software, most often a driver. If the crash names a different file each time, or keeps happening after a clean reinstall of Windows, faulty RAM, an overclock or a failing drive becomes more likely.

Will I lose my files?

No. A blue screen restarts the PC but doesn’t delete files. Still, back up anything important before you try BIOS updates or a reset.

What if nothing works?

Reset the PC with Settings > System > Recovery > Reset this PC and choose Keep my files. If the crash continues after a reset with no extra drivers installed, have the hardware checked.