Best Free Memory Testing Utility



The starting point for Windows memory testing is Microsoft's Windows Memory Diagnostic tool which is built-in to the versions of Windows since Vista. I will use it as the base case when comparing other software. If you are still on Windows XP then you can download an XP version of MemTest and create a bootable floppy disk or optical disk (CD, DVD, BD) to run it. The floppy disk can be created in one step but if you use an optical disk then all you get is an ISO image file for you to burn to an optical disk.

When you run the Memory Diagnostic tool you are simply deciding when you want the memory test to run. The test only runs when you restart your system and it will complete before Windows restarts. When it is running you can press F1 to change the options but you probably won't need to. If you need to exit the test early then you simply press Esc.

Microsoft's tool is a 32-bit application that does not address memory above 4GB. If you have more than 4GB of RAM then you need to use one of the products recommended here.

Also read about Memory Testing at the end of this article.


Rated Products


Provides a lot more information than the Windows memory tester, with more options

Our Rating: 
License: Free (Limited features)
Comprehensive memory testing, can be run from floppy, CD or USB; has more test options than MemTest86+; graphical interface when your system uses UEFI.
Limited console (character-based) interface when your system has a BIOS. It is simple but is better suited for advanced users.
Read full review...


Provides a lot more information than the Windows memory tester, with a small download

Our Rating: 
License: Free (Open source)
Comprehensive memory testing; can be run from floppy, CD or USB, smaller download than MemTest86.
The console (character-based) interface is simple but is best suited for advanced users.
Read full review...

Other Products

I don't recommend older products that are not supported. That includes MemScope and would also include Microsoft's Windows Memory Diagnostic tool except that it provides a matching interface from Windows XP to Windows 10.

I don't recommend running memory tests while Windows is running. There is at least one free product that does this, MemTest, but it should be avoided unless you are an advanced user. First, it tests unused memory whereas most of your problems with be with memory that you are using. Second, if you do not configure it correctly then it will take forever to complete.


Related Products and Links

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Memory Testing

Many unusual and seemingly unrelated computer problems can occur if a computer memory module is malfunctioning. Diagnostic memory testing utilities will help you discover if there are problems with your main memory which is also called RAM. These programs are normally stand-alone because they run when you start your system. Don't get them confused with memory benchmarking tests that determine how fast your memory works i.e. what the data throughput is.

If an error is found then the software cannot normally identify the module with the problem. You then have two choices:

  • Use a hardware tester except that cost limits those to PC assemblers and repairers.
  • Remove or swap out memory modules and continue testing until you no longer have the problem.

You also need to be aware that some memory problems are transient or short-lived so they disappear quickly and it is normally sufficient to restart your computer to avoid further consequences. Other memory problems are intermittent so, for example, they can appear as your computer heats up. Be prepared to take several cycles of testing before you can even confirm that the problem is with memory.

Finally, the tests normally run a minimum of half an hour but you could spend a lot longer testing. If you have an intermittent problem then you may want to run the tests continuously for a day or two until an error is found. It is also possible that such exhaustive testing will not pick up any errors.



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hi all

Can I ask why the original Mem Test86 isn't listed here?

The last time I used the above (admittedly before Passmark got involved with it), it detected RAM problems that Mem Test86+ (the branch or port) missed.

The RAM was later diagnosed as faulty by the reseller, so I'm grateful and glad I was able to provide 'proof' for my RMA, and that my testing was corroborated.



I'm taking over this category so I will be testing MemTest86.
MemTest86 is now reviewed and in the article.

Hi Remah

Thanks for the extremely speedy response and action.

Much obliged.



My computer has 32 gb memory spanning 4 sticks. About a month ago the computer was rebooting with no apparent relation to specific programs I was running. First thought was: hard drive failure -- couldn't find a problem. I then ran the win7 command line utility for memory problem -- couldn't find a problem. Used Mem Test 86 -- found the bad stick, replaced it, now everything is hunky dory. It's a very good app.