0x000000C2BAD_POOL_CALLERStop codeWidely reported

BAD_POOL_CALLER (0xC2): what it means and how to fix it

Updated Oct 25, 2026 · Checked against Microsoft documentation · How this page is made

Quick answer

This error occurs when a piece of software or a driver makes an invalid request to the system memory. It is most often caused by faulty or outdated drivers interfering with how Windows manages memory. To fix it, start by checking for recent driver updates or undoing recent system changes.

What it means

Understanding the Error

Windows uses a section of memory called the "pool" to store data that system components and drivers need to run. When a driver or program tries to interact with this memory incorrectly, Windows stops the system to prevent further damage or data loss. This is what the BAD_POOL_CALLER error represents.

Why It Happens

This error is essentially a communication breakdown. Windows has strict rules about how memory can be requested, used, and released. If a driver tries to free memory that has already been released, requests memory in an invalid way, or uses the wrong "tag" to identify its memory, Windows triggers this stop code. Because drivers operate at a high level of authority within your computer, any mistake they make can force the entire system to shut down immediately.

Identifying the Culprit

While the error code itself is generic, it is usually triggered by a specific driver or software component. If you recently installed new hardware, updated a driver, or installed a new software package, that is the most likely source of the problem. Because this is a kernel-level issue, it can sometimes be triggered by security software or specialized drivers like those used for VPNs or storage controllers.

Common causes

A faulty or outdated device driver is mismanaging system memory.
A recent Windows update has introduced a compatibility issue with existing hardware drivers.
Corrupted system memory or physical RAM issues.
A software application, such as a VPN client, is using an incompatible driver.
A driver is attempting to free memory that is already empty or invalid.

How to fix it

Safest and most likely fixes first. Readers' answers to "Did this fix it?" reorder this list over time.

Update your device drivers
Use this if the error started after installing new hardware or if you have not updated your drivers in a long time.
1. Right-click the Start button and select Device Manager.
2. Look for any devices marked with a yellow exclamation mark.
3. Right-click the device and select Update driver.
4. Select Search automatically for drivers.
5. Restart your computer if any updates were installed.
Did this fix it?
Run the Windows Memory Diagnostic tool
Use this if you suspect your physical RAM might be failing.
1. Click the Start button and type Windows Memory Diagnostic.
2. Select the app from the results.
3. Choose Restart now and check for problems.
4. Wait for the computer to restart and run the test.
5. Check the Event Viewer under the System log for the MemoryDiagnostics-Results entry after the test finishes.
Did this fix it?
Undo recent system changes
Use this if the error began immediately after installing a specific update or piece of software.
1. Open Settings and go to Windows Update.
2. Select Update history.
3. Click Uninstall updates to remove the most recent update if you suspect it is the cause.
4. Restart your computer to complete the process.
Did this fix it?

Is it just you?

25+ Microsoft Q&A threads discuss this, 1 active in the last 30 days. Most recent activity:

Checked Oct 23, 2026. Refreshed automatically every few days.

Sources

Frequently asked questions

Is my computer permanently broken?

No, this is a software-level error. It usually indicates a conflict between Windows and a specific driver, not permanent hardware damage.

Can I fix this by reinstalling Windows?

You can, but it is rarely necessary. Most of the time, updating drivers or removing the problematic software will resolve the issue.

What should I do if the blue screen keeps appearing?

If you cannot boot into Windows, try starting in Safe Mode to uninstall recently added software or drivers.