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Home » Windows 11 » Top 5 Ways to Fix Windows Memory Diagnostic Tool Stuck at 21%

Top 5 Ways to Fix Windows Memory Diagnostic Tool Stuck at 21%

Microsoft Windows comes with a handy tool to diagnose RAM issues on your system. Memory problems can cause your computer to lose information, or it may stop working in certain situations. Using the default Windows Memory Diagnostic tool, you can easily check your computer for memory problems. But at times, the Windows Memory Diagnostic tool gets stuck at 21%. If you frequently face the same, here are the top ways to fix the problem.

Depending on the RAM size, it takes around 15 minutes to 10+ hours to run the Memory Diagnostic tool on Windows. The tool getting stuck on 1%, 21%, or any percentage can confuse end users. While it’s normal for the app to get stuck on 21%, if the estimated time is more than 12+ hours, there might be a system glitch. Let’s troubleshoot the problem.

1. Wait for Some Time

As we mentioned earlier, it may take around up to 10 hours to run the Windows Memory Diagnostic tool on your computer. Sometimes, it gets stuck on 21% for more than five hours. It’s completely normal. You should only start sweating when the tool is stuck for more than 10 hours. If you don’t see any movement within 10 hours, it’s time to go through the steps below to troubleshoot the problem.

2. Disable All Services and Try Again

You should disable apps and services running in the background and try your luck with Windows Memory Diagnostic tool again. You shouldn’t disable required Microsoft services at startup, though. You may encounter glitches during the reboot process.

Step 1: Press Windows + R keys to open the Run menu.

Step 2: Type msconfig and hit the Enter key to open the System Configuration menu.

Step 3: Enable the Hide all Microsoft services option.

Step 4: Click Disable all and move to the Startup tab.

Step 5: Open Task Manager from the following menu.

Step 6: Disable all startup apps and services from the following menu.

Reboot your computer and start the system in Clean Boot mode. You can run the Windows Memory Diagnostic tool again and check RAM problems without any issues.

3. Enable Cache

You can enable cache while running the Windows Memory Diagnostic Tool.

Step 1: When you are on the blue screen of the Memory Diagnostic tool, press the F1 key.

Step 2: Use the Tab key to move down to the Cache option.

Step 3: Select On and hit F10 to apply the change.

4. Use MemTest86

The MemTest86 trick will help you determine if the Windows Memory Diagnostic tool getting stuck at 21% is due to the physical RAM or any issue with the software itself.

First, make sure you have a bootable USB stick with you and follow the instructions below to run Windows Memory Diagnostic tool without any issues.

Step 1: Head to the official website to download MemTest86 on your computer.

Step 2: Open File Explorer (use Windows + E keys) and find your downloaded file.

Step 3: Right-click on the folder and select Extract All from the context menu.

Step 4: Connect your USB drive to the computer.

Step 5: Run the imageUSB.exe file from the extracted folder.

Step 6: Make sure to detect the connected drive in the ImageUSB window.

Now turn off your computer, plug in a USB pen drive, and turn on the system. The tool will automatically run after you restart the computer.

5. Run Windows Security Tool

Do you frequently download apps and media files from unknown sources on the web? You might have infected the PC with bogus files. Instead of trying any random third-party anti-virus app, use the built-in Windows Security tool to remove malicious files and run the Windows Memory Diagnostic tool without any issues.

Step 1: Press the Windows key and search for Windows Security.

Step 2: Hit Enter to open the app.

Step 3: Select Virus & threat protection from the left sidebar.

Step 4: Run a quick scan on your computer and remove harmful files.

Try running the Windows Memory Diagnostic tool again, and it won’t get stuck to 21%.

Identify RAM Issues on Windows

Windows Memory Diagnostic tool getting stuck at 21% can confuse you. Instead of waiting for hours, use the tricks above and fix such glaring issues in no time.

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Parth Shah

Parth previously worked at EOTO.tech covering tech news. He is currently freelancing at WindowsPrime, Android Police, and GuidingTech writing about apps comparisons, tutorials, software tips and tricks, and diving deep into iOS, Android, macOS, and Windows platforms.

1 thought on “Top 5 Ways to Fix Windows Memory Diagnostic Tool Stuck at 21%”

  1. If you have a virus infecting the ram it is using the cache to keep itself alive, so you need to turn the cache off to remove the infection; not on, which I know quite well after exposure to this issue for nearly a year with it preventing me from using the windows boot repair tool


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