How to Fix WHEA_UNCORRECTABLE_ERROR in Windows 11

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Ankit Kumar
Windows 11BSODHardwareTroubleshootingFix

The Problem

A WHEA_UNCORRECTABLE_ERROR in Windows 11 is different from most blue screens. WHEA stands for Windows Hardware Error Architecture — the subsystem that listens for fault reports coming from the CPU, memory controller, and PCIe bus. This stop code means a physical component reported an error that could not be corrected, and Windows halted rather than continue with bad data.

That makes it one of the few stop codes that is usually genuine hardware, not a driver bug. The four realistic causes, in order of how often they turn out to be the culprit: an unstable overclock or undervolt, failing RAM, a failing or overheating CPU, and a dying power supply.

Not sure the stop code is really this one? Photograph the screen and start with how to fix a BSOD. PC also restarts with no blue screen at all? See Windows 11 freezing and crashing randomly.

Symptoms

  • Blue screen reading WHEA_UNCORRECTABLE_ERROR, sometimes with a stop code of 0x00000124.
  • Crashes cluster under load — gaming, video export, a Windows update, or a virus scan.
  • The PC restarts instantly with no blue screen at all, especially on a desktop with an aggressive overclock.
  • Event Viewer logs WHEA-Logger events under Windows Logs → System.

Step 1: Remove Every Overclock and XMP Profile

This is the single most common cause and the fastest thing to rule out.

  1. Restart and enter firmware setup — see how to enter BIOS or UEFI.
  2. Load Optimized Defaults (sometimes "Load Setup Defaults" or F9).
  3. That also disables XMP / EXPO memory profiles, dropping RAM to its safe JEDEC speed. Leave it off for now.
  4. If you use a CPU undervolt from Intel XTU, Ryzen Master, or a motherboard "Curve Optimizer" setting, reset it to stock as well.
  5. Save, exit, and use the PC normally for a day.

If the crashes stop, the overclock was unstable. Reapply XMP alone first; if that is stable for a day, then reapply any CPU tuning in smaller increments.

Step 2: Read the WHEA Event to Find the Reporting Component

The event log names which piece of hardware raised the error.

  1. Press Windows + R, type eventvwr.msc, press Enter.
  2. Expand Windows Logs → System.
  3. Click Filter Current Log in the right pane, and in Event sources tick WHEA-Logger.
  4. Open the most recent error and read the Details tab.

Look for these fields:

  • Processor APIC ID or "A fatal hardware error has occurred… Reported by component: Processor Core" — points at CPU or its power delivery.
  • Memory or "Error Source: Corrected Machine Check" naming a DIMM — points at RAM.
  • PCI Express Root Port with a bus/device/function number — points at a card or NVMe drive in that slot.

A full walkthrough of the log viewer is in how to use Event Viewer to find why your PC crashed.

Step 3: Test the RAM Properly

  1. Press Windows + R, type mdsched.exe, choose Restart now and check for problems.
  2. When it boots into the test, press F1, set Test Mix to Extended, and let it run at least one full pass.
  3. Windows Memory Diagnostic is a quick screen, not a thorough one. If it passes but you still suspect RAM, run MemTest86 from a USB stick for four or more passes overnight.
  4. Any error at all means bad memory. Test one stick at a time in the same slot to identify which one, then test the good stick in each slot to rule out the slot itself.
  5. Related, for a different memory stop code: fix MEMORY_MANAGEMENT BSOD.

Step 4: Check CPU Temperature and Throttling

A CPU that overheats under load reports uncorrectable machine-check errors before it shuts down.

  1. Open Task Manager (Ctrl + Shift + Esc) → Performance → CPU and watch the clock speed while the PC is busy.
  2. Install a temperature monitor such as HWiNFO and record the peak core temperature during a 10-minute load.
  3. Sustained temperatures above 95 °C on desktop or laptop silicon mean cooling is the problem, not Windows.
  4. Full procedure: fix CPU overheating and thermal throttling and fix loud fan noise.

Step 5: Update Chipset Firmware and Drivers

WHEA errors on newer platforms are often fixed by a BIOS update that corrects memory training or power management.

  1. Note your motherboard or laptop model from Windows + R → msinfo32 → System Model and BIOS Version/Date.
  2. Download the latest BIOS/UEFI and chipset drivers from the manufacturer's own site — not a driver-updater tool.
  3. Install the chipset driver first, reboot, then apply the firmware update following the vendor's instructions exactly.
  4. Do not flash firmware on a laptop running on battery, or on a desktop during a storm without a UPS.
  5. General guidance: how to update outdated drivers.

Step 6: Rule Out the Storage Controller and Drive

A failing NVMe drive on a PCIe root port reports through WHEA too.

  1. Open Terminal (Admin) and run: 
    chkdsk C: /scan
  2. Check the SMART attributes properly: check SSD and hard drive health.
  3. If the WHEA event named a PCI Express Root Port, reseat that card or drive with the PC unplugged, and try a different slot if one is free.

Step 7: Repair Windows System Files

This will not fix true hardware faults, but it removes corruption from the list of suspects.

  1. Open Terminal (Admin) and run in order: 
    sfc /scannow

    DISM /Online /Cleanup-Image /RestoreHealth
  2. Reboot and run sfc /scannow once more to confirm it reports no violations.
  3. Detailed walkthrough: how to run SFC and DISM.

Step 8: Test the Power Supply and Reduce the Load

A PSU that cannot hold voltage under transient load produces exactly this stop code on desktops.

  1. Unplug non-essential drives, extra fans, and RGB controllers.
  2. If you have a spare known-good PSU of adequate wattage, swap it in — this is the only reliable test.
  3. On a laptop, test with the original charger; a low-wattage third-party charger causes the same instability under load.
  4. In Settings → System → Power & battery → Power mode, select Balanced to cap peak draw while testing.

What Not to Do

  • Don't just reinstall Windows first. WHEA is hardware-reported; a clean install almost never fixes it and costs you a day.
  • Don't disable WHEA logging or the Machine Check Exception in BIOS. That hides the report, not the fault, and lets bad data reach your files.
  • Don't run a driver-updater utility. Get firmware and chipset drivers from the hardware vendor only.

Still Not Working?

If defaults are loaded, RAM passes MemTest86, temperatures are normal, and firmware is current, you are down to CPU, motherboard, or PSU. Test with the minimum viable configuration — one RAM stick, integrated graphics, boot drive only. If it is stable there, add components back one at a time.

Before any hardware swap, get your data somewhere safe: set up automatic backups.

Related: fix IRQL_NOT_LESS_OR_EQUAL and fix CLOCK_WATCHDOG_TIMEOUT.

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