If you’re encountering application failures, operating system faults, or Stop errors, you could have defective or failing RAM. The Windows Memory Diagnostic Tool in Windows can help you test the RAM chips in your system.

Launching Windows Memory Diagnostic

There are actually several ways that you can launch the Windows Memory Diagnostic Tool. The method that you will use will depend on your situation.

You can launch Windows Memory Diagnostic from the System Recovery Options menu. However, if you are experiencing intermittent problems and can still boot into Windows. You can launch the Windows Memory Diagnostic Tool by clicking the Start button, than run, type in “MdSched.exe”

When you see the Windows Memory Diagnostic dialog box, as shown in Figure A, click the Restart Now and Check for Problems option. When you do, the dialog box will close and your system will automatically restart.

Figure A

To start Windows Memory Diagnostic, click the Restart Now and Check for Problems option.

Running and testing

Regardless of the way you launch it, once the Windows Memory Diagnostic Tool screen appears, the test will commence. (Note that in this command-line version, the name now has the word Tool appended to it.) As the test advances, you’ll see the progress marked as a percentage and a progress bar, like the one shown in Figure B. As it works, the Windows Memory Diagnostics Tool performs its test by repeatedly writing values to the memory and then reading those values back from memory in order to verify that the data has not changed.

Figure B

Once the Windows Memory Diagnostic Tool’s white-on-blue screen appears, the test will commence.

By default, Windows Memory Diagnostic Tool runs the Standard test, but you can run two other types of tests. To change the test type, press [F1] to access the Options screen, shown in Figure C.

Figure C

The Windows Memory Diagnostic Tool’s Option menu allows you to choose a Basic as well as an Extended type of test.

In the Test Mix section of the Options screen you can chose the Basic test, which runs a limited number of tests, or the Extended test, which runs an exhaustive set of tests. In fact, the Extended mix is so exhaustive that it will often run for eight or more hours.

Each test mix has default cache settings, which should be optimal to that particular test. However, you can use [Tab] to access the Cache section of the screen and choose a custom cache setting. In the case of these tests, the cache being tested is cache on the microprocessor that is used to hold data retrieved from memory modules. While some tests use the cache, other tests disable the cache in order to force the processor to access all the data from the memory module.

Each test will repeat two times by default. However, you can press [Tab] to access the Pass Count section and choose the number of times that you want the test to repeat. Once you make your selections, pressing [F10] will apply the settings and start the test.

As the tests run, the Status area will let you know if problems are found. However, you don’t have to stay glued to the screen, because the Windows Memory Diagnostic Tool can identify and avoid using the problem section of the chip. By identifying those sections, the tool will allow Windows  to start up normally without crashing.

Once Windows restarts and you log on, the test results report will be available from the notification area, as shown in Figure D.

Figure D

A pop-up from the notification area will allow you to display the test results report.

You can also find the test results report by using Event Viewer. Just look in the System Event Log under Source and find MemoryDiagnostics-Results and then under Event ID it should read 1201, as shown in Figure E.

Figure E

The test results can also be found in Event Viewer.