Fix Machine Check Exception BSOD Error in Windows

If you are seeing the Machine Check Exception (WHEA_UNCORRECTABLE_ERROR) Blue Screen of Death, the fix is to identify which hardware component is failing and then update drivers, adjust BIOS settings, or replace the faulty part. This error is almost always caused by hardware problems, not Windows itself, so the solution involves testing your CPU, RAM, GPU, and storage.

What Is the Machine Check Exception BSOD?

The Machine Check Exception (MCE) is a hardware error that the CPU detects and reports. When the CPU encounters a fatal internal problem—like a cache error, a bus error, or a thermal issue—it triggers a machine check, and Windows crashes with the stop code WHEA_UNCORRECTABLE_ERROR (0x00000124). This is different from a software crash because the system cannot continue safely when the processor itself is compromised.

The error often appears randomly, during heavy load, or even at idle. It can happen on both laptops and desktops, and it is more common on overclocked systems or older machines with failing components.

Common Causes and How to Diagnose Them

Before you start swapping parts, you need to narrow down the culprit. The most frequent causes are:

Overheating CPU or GPU – Check temperatures with a tool like HWMonitor or Core Temp. If your CPU exceeds 90°C under load, thermal throttling or shutdowns may occur.
Faulty RAM – Use Windows Memory Diagnostic or MemTest86 to test your memory sticks.
GPU issues – Run a stress test like FurMark or Unigine Heaven to see if the error appears during graphics-heavy tasks.
Power supply problems – A failing PSU can cause instability, especially under load.
Driver incompatibility – Outdated or corrupted drivers, especially for chipset or graphics, can trigger the error.
BIOS/UEFI settings – Overclocking settings, XMP profiles, or outdated BIOS firmware can cause instability.

Step-by-Step Fixes to Try

Start with the least invasive steps and move to more complex ones.

Update Windows and drivers – Go to Settings > Update & Security > Windows Update, and install all pending updates. Then update your chipset, GPU, and network drivers from the manufacturer’s website.
Check for overheating – Clean dust from fans, ensure proper airflow, and reapply thermal paste if your CPU is old. Test with a stress tool like Prime95.
Reset BIOS to default – Restart your PC and enter BIOS (usually by pressing Del or F2 during boot). Load default settings, disable any overclocking, and set XMP to auto.
Test RAM – Run Windows Memory Diagnostic (type it in Start) and let it complete. If errors appear, test each stick individually.
Test GPU – Use a GPU stress test. If the error occurs, try reseating the GPU or using a different PCIe slot.
Check event viewer – Open Event Viewer > Windows Logs > System, look for WHEA-Logger events with ID 18 or 19. The details often mention the source (e.g., “Processor Core” or “PCI Express”).
Update BIOS – Download the latest BIOS from your motherboard manufacturer’s site and flash it. This often improves hardware compatibility.

What to Do If the Error Persists

If you have tried the above and the error still occurs, the issue is likely a failing hardware component. Here is how to isolate it:

Remove unnecessary hardware – Unplug extra drives, USB devices, and expansion cards. Boot with minimal hardware to see if the error goes away.
Test with a different PSU – If you have a spare, swap it in. A dying power supply can cause random crashes.
Check the CPU – Reseat the CPU and check for bent pins. If you have an overclocked CPU, revert to stock clocks.
Test with a live Linux USB – If the error occurs in Linux as well, it is definitely hardware. If it only happens in Windows, it could be a driver issue.

If you identify a specific component, replace it. For laptops, this often means taking it to a repair shop.

Prevention and Long-Term Stability

Once the error is fixed, take steps to prevent it from returning:

Keep your system cool – Ensure fans are working and consider a better CPU cooler.
Avoid aggressive overclocking – If you must overclock, do it gradually and stress test.
Use a surge protector – Power fluctuations can damage components.
Update drivers regularly – Set up automatic driver updates for critical components.
Monitor event log – Periodically check for WHEA warnings that may indicate a developing problem.

Frequently Asked Questions

Can a software update fix the Machine Check Exception?

Sometimes. If the error is caused by a faulty driver or a Windows bug, updating the driver or Windows can resolve it. However, if the hardware is physically failing, no software update will help.

Is the Machine Check Exception always a CPU problem?

No. While the CPU reports the error, the source can be the CPU itself, the motherboard, the RAM, the GPU, or even the power supply. The event log often points to the specific device.

How do I read the WHEA-Logger event details?

Open Event Viewer, go to Windows Logs > System, and filter by source “WHEA-Logger”. Look for events with ID 18 or 19. The “Error Source” field will say “Machine Check Exception” and the “Error Type” may indicate a cache, bus, or other error. The “APIC ID” can help identify the core.

Will resetting BIOS clear the error?

It can, if the error is caused by unstable overclocking or incorrect voltage settings. Reset to default and test. If the error persists, it is likely a hardware fault.

Should I replace my CPU if I get this error?

Only after you have ruled out other components. Test RAM, GPU, and PSU first. If the error consistently points to the CPU (e.g., in event log and stress tests), then replacing the CPU may be necessary.

Can this error be caused by a virus?

No. The Machine Check Exception is a hardware-level error and is not caused by malware. However, malware can cause system instability that might trigger other BSODs, but not this specific one.

General steps for current mainstream versions; menus can differ by device and version. See the disclaimer or report an error.

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