0XC000036A

STATUS_MCA_OCCURED (0XC000036A) – Machine Check Error Fix

Windows Errors Intermediate 👁 8 views 📅 Jun 17, 2026

This error means your CPU detected a hardware fault—often bad RAM, overclocking, or a failing PSU. Here's how to pin down the cause and fix it.

When does this error show up?

You're working away—maybe gaming, running a render, or even just browsing—and suddenly the screen freezes. Then you get a blue screen with the error code 0XC000036A and the message STATUS_MCA_OCCURED. It can happen during boot, under load, or sometimes at idle. I've seen it most often on machines with overclocked CPUs or mismatched RAM sticks.

What actually causes it?

This error comes from the Machine Check Architecture (MCA) built into your CPU. The CPU detects an internal hardware error—like a memory parity fault, cache corruption, or a voltage spike—and raises the alarm. Windows catches that signal and throws this stop code.

Plain English: your computer knows something physical went wrong inside the processor or its connected parts. It's not a software bug you can patch out. The culprit is usually one of these:

  • Bad RAM – the #1 cause in my experience. A single bad memory cell can trigger this.
  • Unstable overclock – pushing your CPU or memory too far.
  • Failing power supply – dirty voltage or insufficient wattage causes the CPU to choke.
  • Overheating CPU – thermal throttling can turn into a machine check if it gets severe.
  • Motherboard or CPU defect – less common, but possible.

Step-by-step fix

Work through these in order. Don't skip unless you're sure about a specific cause.

Step 1: Check Windows Event Log for the exact hardware source

This is the fastest way to know which part is failing.

  1. Press Win + X and click Event Viewer.
  2. In the left pane, expand Windows Logs > System.
  3. On the right, click Filter Current Log…
  4. In the dropdown for Event sources, check WHEA-Logger and Microsoft-Windows-WHEA-Logger. Click OK.
  5. Look for events with Event ID 18 or Event ID 47. These are machine check errors.
  6. Double-click one. In the General tab, read the description. It might say something like "A fatal hardware error has occurred. Component: Memory." Or it'll list a cache or bus error.

What you'll see after: The event tells you which component triggered it—Memory, Cache, or Bus. That's your starting point.

Step 2: Run a memory test

If the log says Memory, or you're not sure yet, test your RAM first.

  1. Open Windows Memory Diagnostic (search for it in the Start menu).
  2. Select Restart now and check for problems.
  3. The PC restarts and runs a basic memory test. Let it finish. It takes 10–20 minutes.
  4. If it finds errors, you have bad RAM. Replace the failing stick.

If the basic test passes but you still get crashes: Run a deeper test. Download MemTest86 (free version) and boot from a USB stick. Let it run for at least 2 full passes (can take a few hours). MemTest86 catches errors the Windows tool misses.

Step 3: Reset overclocks to stock

If the event log points to Cache or Bus, or you have an overclocked system, revert everything to default.

  1. Restart the PC and enter BIOS/UEFI (usually Del or F2 during boot).
  2. Look for a setting like Load Optimized Defaults, Reset to Default, or Restore Default Settings. Apply it.
  3. If you have XMP/DOCP enabled for RAM, disable it for now. Set memory to stock JEDEC speed (usually 2133 MHz or 2400 MHz).
  4. Save and exit.

After rebooting: The system runs at safe speeds. If the error stops, your overclock was the problem. You can try a more conservative overclock later, but keep an eye on stability.

Step 4: Check CPU temperature under load

Heat can cause machine checks. A quick check:

  1. Download HWMonitor (free) or use Core Temp.
  2. Open it and look at the CPU temperature sensors. Note idle temps (should be 30–50°C).
  3. Run a stress test like Prime95 for 10 minutes. Watch the max temperature.
  4. If it hits 95°C or higher, you have a cooling problem. Clean dust from fans, reseat the cooler with fresh thermal paste, and ensure the fan curve is set to kick in earlier.

Step 5: Test your power supply

A failing PSU can cause voltage dips that trip machine checks. This is harder to test without a multimeter or a PSU tester, but you can do a quick check:

  1. Unplug all non-essential peripherals (USB devices, extra drives, RGB controllers).
  2. If you have a dedicated GPU, unplug it and use integrated graphics (if available).
  3. Run the system under load. If the error goes away, your PSU might be too weak or faulty.

If you have a spare PSU or can borrow one, swap it in to confirm.

Still failing? Check these two things

If you've done all the steps above and the error still crashes your system:

  • Update your motherboard BIOS. Manufacturers release microcode updates that improve machine check handling. Check your motherboard manufacturer's support site for the latest BIOS. Flash it following their instructions exactly. I've seen a BIOS update alone fix this error on a few machines.
  • CPU or motherboard defect. If the event log consistently shows a Cache error on the same CPU core, and you've ruled out RAM, overclocking, heat, and PSU, the CPU itself might be faulty. You may need to RMA it. Same for a motherboard—especially if the error references Bus/Interconnect and memory tests pass.

In rare cases, a Windows update or driver can trigger a false machine check, but that's extremely uncommon. The real fix is almost always hardware-related.

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