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0x00000124WHEA_UNCORRECTABLE_ERRORStop codeWidely reported

WHEA_UNCORRECTABLE_ERROR (0x124): what it means and how to fix it

By Gaurav Rawat · Updated Oct 2, 2026 · Checked against Microsoft documentation · How this page is made

Quick answer

WHEA_UNCORRECTABLE_ERROR means the hardware itself reported an error it couldn't recover from, usually the CPU, memory or the link between them. Unstable overclocks or memory profiles (XMP/EXPO), overheating and outdated BIOS are the usual causes. Return everything to stock settings first.

What it means

WHEA stands for Windows Hardware Error Architecture, the part of Windows that receives error reports from the hardware itself. Bug check 0x124 means the processor, memory controller or another component flagged an error serious enough that Windows can't safely continue.

That makes it different from most blue screens. A driver isn't misbehaving; the hardware is saying something went wrong. The most common reason on home PCs is a system pushed past what it can do reliably: an overclock, an aggressive memory profile, an undervolt, or simply heat.

Read the WHEA-Logger events

Before each crash, Windows usually logs a WHEA-Logger event in Event Viewer (Windows Logs > System). Its details often say which component reported the error, such as a processor core, the cache or a PCI Express device. That points you at the right fix.

Common causes

  • Overclocking or undervolting the CPU or graphics card.
  • An XMP or EXPO memory profile that isn't stable on your system.
  • Overheating from dust, failed fans or dried-out thermal paste.
  • An outdated BIOS/UEFI, especially on newer CPUs.
  • Failing hardware: memory, CPU, motherboard or a PCIe device.

How to fix it

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

  1. Undo overclocks and memory profiles

    If you've enabled XMP/EXPO, overclocked or undervolted anything, or the crashes happen under load.

    1. Restart into your BIOS/UEFI setup (usually Delete or F2 as the PC starts).
    2. Load optimised defaults, or turn off XMP/EXPO and any CPU or GPU overclock or undervolt.
    3. Close or uninstall GPU tuning tools that apply settings at startup.
    4. Use the PC for a few days on stock settings to see if the crashes stop.
    Did this fix it?

  2. Update your BIOS/UEFI

    If your BIOS is more than a few versions behind, or your CPU is a recent model.

    1. Press Win + R, type msinfo32 and note BIOS Version/Date and your motherboard or system model.
    2. Download the newest BIOS for that exact model from the manufacturer's support page.
    3. Follow the maker's instructions precisely, without interrupting power, then reset settings to defaults.
    Did this fix it?

  3. Check temperatures

    If crashes happen under load or in warm rooms.

    1. Clean dust from fans, heatsinks and vents.
    2. Make sure every fan spins when the PC is busy.
    3. On a desktop older than a few years, consider replacing the CPU's thermal paste.
    Did this fix it?

  4. Test your RAM

    If the crashes are random, or this stop code alternates with other memory-related ones.

    1. Save your work, press Win + R, type mdsched.exe and press Enter.
    2. Choose Restart now and check for problems, and let the test run to the end.
    3. When Windows starts, check the result notification, or Event Viewer > Windows Logs > System, filtered for MemoryDiagnostics-Results.
    4. Any errors mean a memory problem. Reseat the sticks, test them one at a time, and replace any that fail.
    Did this fix it?

Is it just you?

25+ Microsoft Q&A threads discuss this. Most recent activity:

Checked Oct 2, 2026. Refreshed automatically every few days.

Sources

Frequently asked questions

Is WHEA_UNCORRECTABLE_ERROR always a hardware failure?

Not always failing hardware, but always hardware-reported. Unstable overclocks and memory profiles cause it far more often than broken parts.

Can XMP cause WHEA_UNCORRECTABLE_ERROR?

Yes. If the memory or memory controller isn't stable at the XMP or EXPO settings, turning the profile off often stops the crashes.

Can a Windows update cause WHEA_UNCORRECTABLE_ERROR?

Rarely directly, but an update can expose an unstable system. Check stock settings and BIOS updates before blaming the update.

Written by

Gaurav Rawat

Gaurav Rawat is a full-stack developer from Jaipur with a B.Tech in Information Technology. At PC Decoder, he writes practical guides on Windows 11 updates, error codes, and fixes for apps that stop working after an update, with an emphasis on clear steps that actually solve the problem.

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