Windows Memory Diagnostic

A full review of Windows Memory Diagnostic, a free RAM testing tool

Windows Memory Diagnostic (WMD) is an excellent free memory test program. Windows Memory Diagnostic is a comprehensive memory test but is also very easy to use.

The BIOS in your computer will test your memory during the POST but it's an extremely basic test. To truly determine if your RAM is not working properly, you must perform an extensive memory test by a program like Windows Memory Diagnostic.

MATS+ test on Windows

We recommend that you first test your memory with Memtest86, but you should always test a second time with a different memory testing tool just to be sure. Windows Memory Diagnostic should be that second tool.

WMD used to be available directly from Microsoft but no longer is. The link above is to Softpedia which also hosts the download.

Windows Memory Diagnostic Pros & Cons

While not the best RAM test tool out there, it's a great second option:

What We Like
  • The program is completely free to use by anyone

  • Extremely small download

  • Windows does not need to be working or installed to use the tool

  • Easy enough for anyone to use and benefit from

  • No user intervention required—memory test is completely automatic

What We Don't Like
  • Creation of startup disk and CD image adds extra steps

  • Will only test the first 4GB of RAM

More About Windows Memory Diagnostic

  • Windows Memory Diagnostic contains extended test options but none are necessary for a standard memory test
  • Multiple tests are performed to locate the obscure memory hardware problems
  • Windows Memory Diagnostic memory test sets will continue to repeat until the PC is powered off
  • No operating system is necessary to run memory tests
  • Windows Memory Diagnostic is included as part of the System Recovery tools in Windows 7

Our Thoughts on Windows Memory Diagnostic

Windows Memory Diagnostic is one of the better free memory testing programs available. We've used it for years as a second opinion when Memtest86 finds a memory failure.

You do not need Windows installed nor do you need to own a copy to use WMD. Microsoft developed the program, that's all.

To get started, visit the Microsoft's Windows Memory Diagnostic download page on Unfortunately, Microsoft no longer hosts this program.

Once there, choose DOWNLOAD NOW on the left, and then pick one of the download links; either should work.

Once downloaded, run mtinst.exe. Select Accept and then Save CD Image to Disk, and save the windiag.iso ISO image to your desktop. You can select OK on the confirmation prompt and then close the other window.

Now you have to burn the ISO file to a CD. We haven't been able to get WMD burned properly to a USB drive, like a flash drive, so you'll need to use a disc.

Burning an ISO file is different than burning other kinds of files.

After writing the ISO image to the CD, boot to the CD by restarting your PC with the disc in the optical drive. Windows Memory Diagnostic will start immediately and begin testing your RAM.

If WMD doesn't start (for example, your operating system loads as normal or you see an error message), then see the instructions and tips in How to Boot From a CD or DVD.

Windows Memory Diagnostic will continue to make an infinite number of passes until you stop it. One pass without error is usually good enough. When you see Pass #2 start (in the Pass column) then your test is complete.

If WMD does find an error, replace the RAM. Even if you aren't experiencing any problems right now, you likely will in the near future. Save yourself frustration later and replace your RAM now.

Windows Memory Diagnostic is included as part of System Recovery Options in Windows 7 and Windows Vista.

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