Windows & BSOD · critical

How to fix PAGE_FAULT_IN_NONPAGED_AREA0x00000050

Windows & BSOD troubleshooting guide

What this error means

Windows stopped because it tried to use system memory at an address that is not valid, usually a wrong address or memory that was already freed. Microsoft lists three main sources: a faulty driver or system service, antivirus software, and a damaged NTFS file system. Failing hardware is the other common cause, typically defective RAM, including the memory on the graphics card. The blue screen often names the driver that made the bad access.

Updated

Applies to
Windows 11 and Windows 10
Difficulty
Beginner to intermediate
Before changes
Low for steps 1–6; Driver Verifier in step 7 can cause extra crashes until it is turned off

Reviewed by Matyáš Rada · Documentation checked: 2026-10-30 · Checked against Microsoft's bug check documentation; not tested on every configuration.

Before you begin

Photograph the blue screen, especially any "What failed" file name. If Windows crashes during startup, use Safe Mode or the recovery environment for the steps below. If Windows cannot start, see the startup guide.

Work through these checks

0 of 7 complete
01Find the driver named in the crash

When the bad memory access comes from a driver, Windows usually names it.

  1. Look for "What failed: name.sys" on the blue screen and search the file name to find its device or program.
  2. Open Event Viewer (Win + R, eventvwr.msc) > Windows Logs > System and check critical errors from the same time.
  3. Install the newest version of that driver from the device maker.
What to expect

The named driver is updated and the crash stops.

If it does not help

If no file is named, or it is a Windows file such as ntoskrnl.exe, continue with step 2.

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02Undo recent driver, service or antivirus changes

Microsoft names faulty drivers, system services and antivirus software as the main software causes.

  1. Roll back a recently updated driver: Device Manager > device Properties > Driver > Roll Back Driver.
  2. Uninstall third-party antivirus, VPN or system tuning software in Settings > Apps > Installed apps and test again.
  3. If the crash started after a Windows update, uninstall it in Settings > Windows Update > Update history > Uninstall updates.

Microsoft Defender turns on automatically when you remove another antivirus; keep it on.

What to expect

The crash stops after the change is undone.

If it does not help

If a program was responsible, contact its maker or install a newer version later.

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03Test the memory

Defective RAM is the most common hardware cause of invalid memory references.

  1. Turn off XMP, EXPO and any memory overclock in the BIOS for testing.
  2. Run Windows Memory Diagnostic (Win + R, mdsched.exe) > Restart now and check for problems.
  3. After the restart, find the result in Event Viewer > Windows Logs > System, source MemoryDiagnostics-Results.
What to expect

The memory test passes.

If it does not help

If it reports errors, follow the memory test errors guide on this site. If crashes happen only in games, the graphics card's memory can also be at fault; test with the card's stock clocks.

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04Check the drive for file system errors

Microsoft lists a corrupted NTFS volume as a cause of this stop code.

  1. Open Terminal (Admin) and run chkdsk C: /f /r.
  2. Answer Y to schedule the check, restart, and let it finish without interrupting it.
  3. Check the drive's health in its maker's tool.

Chkdsk /r on a large hard drive can take hours. Back up important files first if the drive may be failing.

What to expect

Chkdsk finishes and fixes any errors; the drive reports good health.

If it does not help

If the drive reports bad sectors or poor health, back up and replace it.

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05Repair Windows system files

After file system errors or crashes, Windows files can be damaged.

  1. Open Terminal (Admin).
  2. Run DISM /Online /Cleanup-Image /RestoreHealth.
  3. Run sfc /scannow, then restart.
What to expect

SFC reports no integrity violations, or that it repaired them.

If it does not help

If problems remain, run both commands again after a restart.

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06Check recently added hardware

Microsoft recommends removing new hardware and running the maker's diagnostics when hardware may be at fault.

  1. Remove hardware added shortly before the crashes started, such as RAM, a graphics card, an expansion card or USB devices, and test again.
  2. Run the hardware diagnostics from your PC or laptop maker.
  3. On a desktop, reseat the RAM modules and the graphics card.

Switch off and unplug the PC before opening it.

What to expect

You find whether a specific device causes the crash.

If it does not help

Replace hardware that fails the maker's diagnostics.

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07Find the driver with Driver Verifier

If no driver is named, Driver Verifier makes the faulty one show up in the next crash.

  1. Create a restore point (search "Create a restore point").
  2. Open Command Prompt (Admin), type verifier, choose Create standard settings > Select driver names from a list, and tick only non-Microsoft drivers.
  3. Restart and use the PC until it crashes, then note the driver named.
  4. Turn Driver Verifier off with verifier /reset and restart.

Driver Verifier deliberately crashes the PC when it finds a problem. Turn it off when you are done.

What to expect

A specific driver is named for you to update or remove.

If it does not help

If Windows does not start with Driver Verifier on, start in Safe Mode and run verifier /reset.

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Possible causes

  • A faulty driver or system service
  • Antivirus software
  • Faulty RAM or graphics card memory, or an unstable memory overclock
  • File system errors on the system drive
  • Recently added or failing hardware

Useful Windows tools

These commands open Windows tools. Review changes before applying them.

eventvwr.msc
mdsched.exe

Sources & further reading