Windows & BSOD · critical

How to fix BAD_POOL_CALLER0x000000C2

Windows & BSOD troubleshooting guide

What this error means

Windows stopped because a driver made an invalid request for kernel memory, such as freeing the same memory twice. Requesting memory at a priority level where that is not allowed causes it too. Unlike BAD_POOL_HEADER, where the damage is found later, this code catches the faulty request as it happens, so the driver that made it is often the one named on the blue screen. Microsoft recommends Driver Verifier to find the driver, and a memory test when memory corruption is suspected.

Updated

Applies to
Windows 11 and Windows 10
Difficulty
Intermediate
Before changes
Low for steps 1–5; Driver Verifier in step 6 can cause extra crashes until it is turned off

Reviewed by Matyáš Rada · Documentation checked: 2026-10-31 · Checked against Microsoft's bug check documentation; not tested on every configuration.

Before you begin

Photograph the blue screen, especially the file after "What failed". If Windows keeps crashing at startup, use Safe Mode (recovery menu > Troubleshoot > Advanced options > Startup Settings > Restart > 4). If Windows cannot start, see the startup guide.

Work through these checks

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

This stop code catches the bad request as it happens, so the named driver is usually the culprit.

  1. Look for "What failed: name.sys" on the blue screen and search the file name to find its device or program.
  2. If the PC restarted too quickly, check Event Viewer (Win + R, eventvwr.msc) > Windows Logs > System for errors just before the BugCheck event (ID 1001).
What to expect

You know which driver made the bad request.

If it does not help

If the named file is a Windows file (such as ntoskrnl.exe), the real cause is another driver; go to step 3.

Browse related errors
02Update or roll back that driver

Fixing or replacing the faulty driver removes the bad request.

  1. If the crashes began after a driver update, roll it back in Device Manager > device Properties > Driver > Roll Back Driver.
  2. Otherwise, install the latest version from the device or PC maker.
  3. If the driver belongs to a device you do not need, disable the device in Device Manager to confirm.
What to expect

The PC runs without the stop code.

If it does not help

If the maker has no fixed driver, contact their support with the crash details.

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03Remove recently installed kernel-level software

Antivirus, VPN, virtual network adapters, virtual drives and hardware monitoring tools install their own kernel drivers.

  1. Uninstall such programs that you installed or updated before the crashes began (Settings > Apps > Installed apps).
  2. Restart and test.

Keep Microsoft Defender on while another antivirus is removed.

What to expect

The crashes stop.

If it does not help

Install the latest version later and check whether the crash returns.

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04Test the memory

Microsoft recommends Windows Memory Diagnostic to rule out physical memory when pool corruption is involved.

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

No memory errors are found.

If it does not help

If errors are found, follow the memory test errors guide on this site.

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05Repair system files

Damaged Windows files can make drivers misbehave.

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

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

If it does not help

If the crash continues, identify the driver in step 6.

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06Find the driver with Driver Verifier

Microsoft recommends Driver Verifier with its memory pool options to locate the faulting driver.

  1. Create a restore point (search "Create a restore point").
  2. Open Command Prompt (Admin), type verifier, choose Create standard settings (it includes the pool checks) > Select driver names from a list, and tick only non-Microsoft drivers.
  3. Restart and use the PC until it crashes; the blue screen names the driver.
  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.

Browse related errors
07Undo a recent Windows update

If the crashes began right after an update, an incompatible driver may be reacting to it.

  1. Open Settings > Windows Update > Update history > Uninstall updates and remove the latest update.
  2. Or use System Restore to a point from before the crashes.

System Restore removes apps and drivers installed after the restore point.

What to expect

The crashes stop.

If it does not help

Update your drivers before installing the update again.

Browse related errors

Possible causes

  • A driver bug, such as freeing the same memory twice
  • A recently installed or updated driver
  • Antivirus, VPN or other software with kernel drivers
  • Faulty RAM
  • Damaged system files

Useful Windows tools

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

eventvwr.msc
mdsched.exe

Sources & further reading