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!
Note: This review is of MemTest86 version 5.1.0, released on December 3, 2013. Please let me know if there's a newer version I need to review.
MemTest86 Pros & Cons
If it's not already clear, there's a lot to like about this memory tester:
- 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 CD/DVD or a flash drive
- Very small download
- Advanced features could intimidate novice users
More on MemTest86
- 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 8, Windows 7, Windows Vista, Windows XP, Linux and any other PC operating system, including Intel x86-based Macs.
- 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 images available for disc (CD/DVD) and USB drive (flash drive, etc.)
How To Use MemTest86
The first thing you need to do is visit the MemTest86 website and download the correct file among your two options under Windows Downloads.
If you plan on using MemTest86 from a CD, choose the Image for creating bootable CD (ISO format) download (memtest86-iso.zip). If you're going to us a USB drive, choose Image for creating bootable USB Drive (memtest86-usb.zip) instead.
Both MemTest86 downloads are in ZIP format and so must be un-zipped before they can be used. Windows should give you an option to do this but if not, or you'd rather use a dedicated tool, here are several free zip/unzip programs you can download and install to do the job.
After extracting the contents of the ZIP file, your next steps differ depending on which download you chose:
Bootable CD Method
Locate the ISO image that you extracted from the memtest86-iso.zip file you downloaded (Memtest86-1.1.0.iso) and burn it to a disc. A CD is more than large enough but a DVD or BD is fine if that's all you have.
Burning an ISO file is a bit different than burning other files like, documents or music. If you need help, see my How To Burn an ISO Image File to a Disc tutorial.
After the disc is burned, boot from it instead of your hard drive. MemTest86 will start almost immediately. Skip down to Running Memory Tests for what to do next.
If MemTest86 doesn't start (for example, your operating system loads as normal or you see an error), or if you have no idea what you're doing here, see my How to Boot From a CD, DVD, or BD Disc tutorial for help.
Bootable USB Drive Method
Locate the files you extracted from the memtest86-usb.zip file you downloaded: a small program, imageUSB.exe, and an IMG file, memtest86-usb.img).
Insert a USB drive into your computer that is empty you're fine with having everything erased from. Then execute 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 to UFD.
If for some reason this process doesn't work, try burning the MemTest86 ISO image to a USB drive using my How to Burn an ISO File to USB tutorial.
Once the USB drive is created, boot from it. MemTest86 should start very quickly. Move on to Running Memory Tests below to continue.
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.
Running Memory Tests
On the MemTest86 menu, click on Config. Here you'll see lots of information about your CPU and memory. Click on Start Test to begin the memory test.
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 10 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 computer. By default, MemTest86 will make 4 passes unless you force it to stop.
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.
My Thoughts on MemTest86
MemTest86 is absolutely the best of the free memory testing programs. I'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 I highly recommend you test your memory with MemTest86!