The Bottom Line
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 valuable to both novices and experts alike.
A short memory test is often completed by the BIOS during the POST but the 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!
- Industry standard memory test - same one used by experts
- Completely free diagnostic tool
- Easy enough for anyone to use and interpret results from
- Product is fully supported meaning updates and fixes are planned
- Very small download
- Advanced features could intimidate novice users
- 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.
- Works with Windows 7, Windows Vista, Windows XP, Linux and any other PC operating system.
- Memtest86 can test memory without any operating system installed since it's a standalone diagnostics tool.
- Supports up to 64GB of RAM.
- Memtest86 works with all memory types and supports both 32-bit and 64-bit systems.
Guide Review - Memtest86 v4.0
Memtest86 is absolutely the best of the free memory testing programs. I've used several expensive memory test tools and none compare to Memtest86.
Get started by visiting the Memtest86 website linked above the User Reviews at the bottom of this page. Once there, click on the Free Download link on the left and then download the zipped ISO image to the right. It's a small file so it shouldn't take more than a minute on any connection.
Once downloaded, extract the ISO file and burn it to a CD. Burning an ISO file is a bit different than burning other files like documents or music. If you need help, see How To Burn an ISO Image File to a Disc.
Next, boot to the CD. Memtest86 will start immediately and begin testing your RAM. If Memtest86 doesn't start (for example, your operating system loads as normal or you see an error), then see these tips on booting from discs.
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.
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 8 memory tests are complete then 1 pass has completed.
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 PC. Memtest86 does not stop on its own but will continue to make passes until you stop it.
I 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.
If you're seeing random lock-ups, strange errors, issues during a Windows installation, or you suspect a hardware problem then I highly recommend you test your memory with Memtest86!