The Bottom Line
Windows Memory Diagnostic 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.
I 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.
Note: WMD used to be available directly from Microsoft but no longer is. The link below is to Softpedia which also hosts the download.
- 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
- Creation of startup disk and CD image adds extra steps
- Will only test the first 4GB of RAM
- 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.
Guide Review - Windows Memory Diagnostic
Windows Memory Diagnostic is one of the better free memory testing programs available. I've used it for years as a second opinion when Memtest86 finds a memory failure.
Important: 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 Microsoft's Windows Memory Diagnostic page, linked at the bottom of my review. Once there, click on the Download Windows Memory Diagnostic link and download the mtinst.exe file.
Once downloaded, run the program. The Windows Memory Diagnostic Setup window should appear. Click the Save CD Image to Disk... button and save the windiag.iso ISO image to your desktop.
Now you have to burn the ISO file to a CD. Burning an ISO file is different than burning other kinds of files. If you need help, see How to Burn an ISO Image File to a CD.
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.
Note: 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 Your Computer from a Bootable 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.
Note: Windows Memory Diagnostic is included as part of System Recovery Options in Windows 7 and Windows Vista.