How to Identify RAM Problems with Windows Memory Diagnostic

Sometimes, what seems like a problem with one thing is actually caused by another. One source of odd problems in all kinds of computers is misbehaving memory modules. Fortunately, Windows supplies a very useful tool for diagnosing these things, and it may save you a lot of frustration poking around in your computer's insides. The Windows Memory Diagnostic tool works the same way in Windows 7, Windows 8 and Windows 8.1. Let's get started and see how it works.

How to Start the Windows Memory Diagnostic in Windows 7

If Windows 7 is working properly, you can start Windows Memory Diagnostic by typing memo or memory into the Start Menu search box. Then, click the appropriate search result.

Or you can go to Control Panel -> System & Security -> Administrative Tools -> Windows Memory Diagnostic.

How to Start the Windows Memory Diagnostic in Windows 8 & 8.1

In Windows 8, type memory on the Start screen, choose Settings and then click or tap the search result that says "Diagnose your computer's memory problems".

You can also use the Control Panel and go to System and Security and then Administrative Tools, just like in Windows 7. There you will find the Windows Memory Diagnostic shortcut.

In Windows 8.1, the same Control Panel path applies. The only difference is that, in the Start screen, you need to type memory and then click or tap "Diagnose your computer's memory problems", without having to filter the search results, like you do in Windows 8.

What if Windows Doesn't Work - How to Start the Windows Memory Diagnostic?

If Windows no longer works and you can't start the Windows Memory Diagnostic tool, you can use the Windows installation disc, a system repair disc (How to Create a System Repair Disc for Windows 7 & Windows 8) or a USB memory stick with recovery tools (How to Create a Recovery Drive on a USB Memory Stick in Windows 8 & 8.1).

If you are using Windows 7, read this guide to learn how to access the system recovery tools available: An Overview of System Recovery Options for Windows 7. The Windows Memory Diagnostic tool is found in the System Recovery Options window.

In Windows 8 and Windows 8.1, there is no shortcut available for this tool. It can't be found in the Windows installation disc and neither on the system recovery drive you have created. But, you can still launch it.

When asked to choose an option, click Troubleshoot, then Advanced options and start the Command Prompt.

Type mdsched.exe and press Enter.

The Windows Memory Diagnostic is now launched.

How to Use the Windows Memory Diagnostic Tool

You'll be asked if you want to run the tool to diagnose memory problems. If you're ready to run it now, select "Restart now and check for problems (recommended)". Before you do this, make sure everything you were working on is closed.

And presto, your screen will look like it's been transported back to the DOS era! While you see this screen, the tool is doing its job, trying to identify problems with your computer's RAM.

Once the test is done, your computer will restart. Log in with your username and password. You will see a little pop-up message in the taskbar, telling you the results of the test.

The detailed results of the tests performed by Windows Memory Diagnostic are stored in the Event Viewer. You will find them under Windows Logs -> System.

The source for these events is named MemoryDiagnostics-Results.

How to Use the Advanced Diagnostic Options

As you can see, there's an easy-to-miss indicator in the lower left corner that tells you you can press F1 for more options.

Most people won't need to fiddle with any of that, and indeed, Microsoft recommends using just the standard settings. However, if you're a more advanced user and want to change some of the parameters, you will need to press F1 when the tool starts.

Your choices will be:

  • Test Mix - you can choose between Basic, Standard or Extended diagnostics. Even though their description is rather basic, what is evident is that the complexity and length of the tests that will run, grows from Basic to Standard to Extended. If you want to be absolutely sure there is no problem with your RAM, the Extended test will do the job but the duration of the testing process will increase significantly.
  • Cache - you can choose between Default, On, or Off. Personally, I think it is best to use the default cache setting.
  • Pass Count - type the number of times you want the test to be repeated. The default number is two and it should be good enough for most tests.

Press F10 to apply your settings and start the test.

NOTE: Windows Memory Diagnostic will run the Standard test by default.


Windows Memory Diagnostic is a very useful tool that can help you discover problems with your computer's RAM. Flaky or faulty RAM can cause other problems that may not seem as though they are memory related. Having one easy-to-use diagnostic tool on hand can save a lot of time and trouble (and possibly opening up your computer to re-seat the memory when it isn't really necessary—been there, done that!) Have you used this tool to discover problems? What was your experience? Please let us know about it in the comments.