MemTest86 v10.4 Free Memory Testing Tool Review

A full review of the free RAM testing software

MemTest86 is simply the best free memory test program available today. MemTest86 is very easy to use and equally thorough. It's also one of the few diagnostic tools of any kind that's equally valuable to both novices and professionals alike.

A short memory test is often completed by the BIOS during the POST, but that test is not at all thorough. A complete memory test by an excellent program like MemTest86 is necessary to truly determine if your computer's RAM is working properly.

If you test your memory with only one memory testing program, make MemTest86 that program without a doubt!

MemTest86 v7.5
What We Like
  • Industry standard memory test—same one used by professionals

  • Completely free diagnostic tool

  • Easy enough for anyone to use and interpret results from

  • Product is fully supported, meaning updates and fixes are planned

  • Works from a flash drive

  • Very small download

What We Don't Like
  • Advanced features could intimidate novice users

  • Doesn't include an option for a disc program (only USB)

This review is of MemTest86 version 10.4, released April 20, 2023. Please let us know if there's a newer version we need to review.

More on MemTest86

  • Works with Windows 11, Windows 10Windows 8Windows 7Windows VistaWindows XP, Linux, and any other PC operating system, including Intel x86-based Macs.
  • MemTest86 performs multiple tests to locate the most obscure memory problems.
  • Several advanced options are available but aren't necessary for a standard memory test.
  • MemTest86 is continually updated to support newer memory and computer types.
  • Test set will automatically repeat as often as you want to provide confirmation that the memory passed or failed the tests.
  • MemTest86 can test memory without any operating system installed since it's a standalone diagnostics tool.
  • Supports up to 64 GB of RAM.
  • MemTest86 works with all memory types and supports both 32-bit and 64-bit systems.
  • Bootable image available for USB drives (flash drive, etc.)

How to Use MemTest86

The first thing you need to do is visit the MemTest86 website to download the program.

Before the December 2018 release, MemTest86 was available as a bootable disc program. To use the program from a CD/DVD, you have to download MemTest86 v7.5 or earlier.

  1. Select Download MemTest86 Free to get the ZIP file (, and then open it when it's finished downloading.

    Windows should give you an option to extract the program files from the archive, but if not, or you'd rather use a dedicated tool, there are several free zip/unzip programs you can download and install to do the job.

  2. Locate the files you extracted from the file you downloaded: a small program, imageUSB.exe, and an IMG file, memtest86-usb.img).

  3. Insert a USB drive into your computer that's empty/you're fine having everything erased. Then, open imageUSB.exe.

    Once it starts, check the USB drive you want to use in Step 1, make sure the memtest86-usb.img file is entered in Step 3, and then choose Write.

    imageUSB by PassMark Software

    If for some reason this process doesn't work, try using our tutorial for burning image files to a USB drive.

  4. Once the USB drive is created, boot from it. MemTest86 should start very quickly.

    If booting from a USB drive is new to you, or if Windows starts normally instead of MemTest86, see How to Boot From a USB Device for help.

  5. Continue with the "Running Memory Tests" section below.

Running Memory Tests

  1. On the MemTest86 menu, select Config. Here you'll see lots of information about your CPU and memory. Choose Start Test to begin the memory test.

  2. You'll see two progress bars and several changing letters and numbers in the top-right part of the MemTest86 screen. Don't worry about all the technical information—you don't need to know exactly what it all means.

  3. The Test bar indicates how complete the current memory test is. The Pass bar indicates how complete the entire set of tests is. When all 10 memory tests are complete then 1 pass has completed.

  4. Once one pass has completed without error, the Pass complete, no errors, press Esc to exit message will appear. At this point you can press Esc to stop MemTest86 and reboot your computer. By default, MemTest86 will make 4 passes unless you force it to stop.

We recommend replacing the RAM if MemTest86 finds any errors. Even if you aren't seeing issues with your computer right now, you likely will in the future.

Thoughts on MemTest86

MemTest86 is absolutely the best of the free memory testing programs. We've used several expensive memory test tools and none compare to MemTest86.

If you're seeing random lock-ups, strange errors, issues during a Windows installation, or you suspect a hardware problem, then we highly recommend you test your memory with MemTest86.

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