Before you replace your motherboard, reinstall Windows, or suspect a virus, there is a free, built-in tool that can provide a definitive answer: . This article provides a complete look at what it is, how it works, when to use it, and how to interpret its results. What is Windows Memory Diagnostic? Windows Memory Diagnostic is a reliable, no-cost memory testing tool integrated directly into the Windows operating system (starting with Windows Vista and present in Windows 10 and 11). Unlike third-party tools like MemTest86, WMD runs outside of Windows—typically from the bootloader—allowing it to test memory that is not in use by the operating system.
| Option | Choices | Recommendation | | :--- | :--- | :--- | | | Basic, Standard, Extended | Standard is sufficient for most issues. Use Extended if you suspect rare, intermittent errors. | | Cache | Default, On, Off | Leave on Default . Disabling cache makes tests slower but more thorough. | | Pass Count | 0–99 | Set to 2-4 passes for a reliable check. The default is usually 2. | windows memory diagnostic
If your PC is crashing or behaving erratically, do not waste hours reinstalling drivers or Windows. Spend 30 minutes to run the Windows Memory Diagnostic. It could save you a tremendous amount of time and point you directly to the culprit—bad memory. And if the tool gives you a clean bill of health, you can confidently move on to troubleshoot other components like your storage drive, power supply, or motherboard. Before you replace your motherboard, reinstall Windows, or