Fix STATUS_MEMORY_NOT_ALLOCATED (0xC00000A0) on Windows 10/11

What’s happening with this error?

You’re seeing STATUS_MEMORY_NOT_ALLOCATED (0xC00000A0) – a stop code that pops up as a blue screen or in an application log. It means Windows tried to free a block of virtual memory that was never properly allocated in the first place. This usually happens because a driver or a program is misbehaving – it’s holding a pointer to memory that doesn’t belong to it anymore.

I’ve seen this most often on Windows 10 and 11 machines with recently updated graphics drivers or after a Windows update that borked a third-party driver. One common trigger: plugging in a USB device right after waking the computer from sleep. The system tries to release memory from the old driver state, but it’s already gone.

Alright, let’s get you fixed. Start with the first fix. If it doesn’t work, move to the next one.

Fix 1: Quick check – run a system file scan (takes 30 seconds)

This is the fastest thing to try. Corrupted system files can cause exactly this error.

1. Press the Windows key and type cmd.
2. Right-click Command Prompt and select Run as administrator.
3. In the black window, type this and press Enter:
   

   sfc /scannow

4. Wait for it to finish – it’ll take about 30 seconds to a minute. You’ll see a message like “Windows Resource Protection did not find any integrity violations” or “Windows Resource Protection found corrupt files and repaired them.”
5. If it found and fixed files, restart your computer and test. If the error’s gone, stop here.

If the scan found nothing or the error came back, move to Fix 2.

Fix 2: Update or roll back your graphics driver (takes 5 minutes)

Graphics drivers are the #1 cause of this error in my experience. They’re big, they interact with memory all the time, and they’re often buggy right after a Windows update.

1. Right-click the Start button and select Device Manager.
2. Expand Display adapters – you’ll see your GPU listed (like NVIDIA GeForce RTX 3060 or Intel UHD Graphics).
3. Right-click it and choose Update driver.
4. Click Search automatically for drivers. Windows will check online and install the latest if available.
5. After it finishes, restart your computer.

If the error started after you updated the driver, you need to roll it back instead:

1. In Device Manager, right-click your GPU and select Properties.
2. Go to the Driver tab.
3. Click Roll Back Driver. If the button is grayed out, Windows doesn’t have a previous version saved – skip this and go to Fix 3.
4. Confirm the rollback and restart.

Test after the restart. If it still crashes, move on.

Fix 3: Run a memory diagnostic (takes 15+ minutes)

Physical RAM problems can also throw this error, though it’s less common. Let’s rule it out.

1. Press Windows key + R, type mdsched.exe, and press Enter.
2. In the window that pops up, select Restart now and check for problems (recommended).
3. Your computer will reboot and run the Windows Memory Diagnostic tool. It’ll take about 15-30 minutes. You’ll see a blue screen with a progress bar – just let it run.
4. After it finishes, Windows will restart again and show you the results. If no errors were found, your RAM is fine.

If the diagnostic found errors, you have a bad memory stick. Replace it. If not, keep going.

Fix 4: Run DISM to repair the system image (takes 10 minutes)

Sometimes the corruption is deeper than SFC can fix. DISM is the heavy lifter here.

1. Open Command Prompt as administrator again (same as Fix 1).
2. Type this and press Enter:
   

   DISM /Online /Cleanup-Image /RestoreHealth

3. Wait for it to finish – it can take 5-10 minutes. It’ll show you a progress bar.
4. Once it says “The restore operation completed successfully,” run SFC again:
   

   sfc /scannow

5. Restart your computer.

Test. Still crashing? Let’s go nuclear.

Fix 5: Clean boot to isolate the problem (takes 15 minutes)

A clean boot starts Windows with only the minimum drivers and startup programs. If the error stops, you’ll know a background service or third-party software is the culprit.

1. Press Windows key + R, type msconfig, and press Enter.
2. Go to the Services tab. Check Hide all Microsoft services (do not skip this).
3. Click Disable all – this kills all third-party services.
4. Go to the Startup tab and click Open Task Manager.
5. In Task Manager, disable every startup item by selecting each one and clicking Disable.
6. Close Task Manager, click OK in System Configuration, and restart.

If the error doesn’t appear now, you have a conflict. Re-enable services and startup items one by one until the error comes back – that’s your culprit. Uninstall the offending program or update its driver.

If the error still happens in a clean boot, you might be dealing with hardware that needs replacing – likely the RAM or the motherboard itself. But 90% of the time, one of these five fixes will get you stable again.