How to Check RAM Health on Windows

Computer RAM close up

RAM (Random Access Memory) is used to store short-term information on your PC. It often comes after software issues and hard drive fragmentation in terms of what we blame when there are problems. But how do you check whether your PC has bad RAM? There are a few ways to perform a memory test. As is often the case, you’re likely to glean more info from third-party software than Windows’s handy but relatively simple in-house methods. This guide shows how to check your RAM health in Windows.

Tip: upgrading your RAM? Find the maximum RAM capacity of your computer.

Symptoms of RAM Problems

Before you check your RAM health, you want to know that you’re barking up the right tree. Look for these telltale signs that your RAM is having issues:

  • PC beeps one or more times as it’s starting
  • PC slows down the longer you keep it on
  • PC keeps crashing with/without BSODs
  • Problems accessing files
  • PC showing less RAM in System Information than you have added

How to Check RAM with Windows Memory Diagnostic

The quickest but least in-depth method to check your RAM is to use the Windows Memory Diagnostic. Click Start, type mdsched.exe, then hit Enter. Restart the computer when prompted, and it will boot to the Memory Diagnostic tool.

Windows Memory Diagnostic Tool screenshot

Press F1, then choose whether you want to run the Basic, Standard, or Extended tests, which change how long it takes, as well as the effectiveness of the tests. Windows will reboot automatically when you’re done, and you’ll receive a notification of whether errors were found when you re-enter Windows.

Checking RAM Health With HCI MemTest

HCI MemTest is a rigorous – yet simple – RAM testing tool that you can leave running for several hours, a day, or even several days. If your RAM is healthy, then it shouldn’t detect any errors – no matter how long you leave it running.

It’s very simple to use. Just download the free version, extract it, then open it. In the free version, your only option is to manually set how much RAM you want to test.

HCI MemTest screenshot

The most effective way to use HCI MemTest is to open an instance for every processor thread you have. If I have a 16-core, 32-thread CPU, I’ll need to open 32 instances of MemTest together. Divide the amount of free RAM (available, not total) you currently have by the total number of threads (In my case, 16GB of free RAM amounted to around 512MB per instance) to determine the number of megabytes to enter in each instance. Click Start Testing on each of the instances to begin the test.

HCI MemTest run test screenshot

This memory testing tool can put a bit of strain on your CPU and RAM, so you’ll want to have all programs on your PC closed (if possible), make sure it’s well ventilated, then leave it to perform the RAM test for a few hours.

HCI MemTest is very direct in how it presents information. If you get a message saying “Memory error detected,” then you know you have a problem and will need to look into your BIOS, or even physically check your RAM sticks to make sure they’re plugged in properly.

The longer you run HCI MemTest, the more accurate it will be. If your RAM is in bad health, then within an hour, it may detect dozens of errors. Repeat the test to check your RAM health again, but if this happens, it may be time to replace your RAM (or stop overclocking it!) on your Windows machine.

Good to know: seeing unexplained memory consumption? Learn how to fix high memory usage in Windows.

Test RAM for Errors With MemTest86

If the tools above don’t bring up any errors, but you’re still convinced that RAM is an issue, you may be right, and it’s worth trying this more detailed tool to find out. This long-lived tool was once used mainly for PCs with 32-bit processors (hence the “86” in the name), but these days it’s just as useful for testing memory on more recent 64-bit machines.

Download the free version of MemTest86 that works on systems with UEFI BIOS. If you have an older system with legacy BIOS, download the V4 version next to the Image for creating bootable USB Drive option (or CD if you want to be old-school about it).

MemTest86 download page

Extract the ZIP file to your hard drive, then double-click the “imageUSB.exe” file to open the image creation tool. (You’ll need a USB flash drive that you don’t mind wiping for this.)

Select the USB drive to be processed in Step 1 of the tool, then the current location of the “memtest86-usb” image file in Step 3. (It’ll be where you extracted it earlier.)

Finally, in Step 4, click the Write button, reboot your PC, and it will boot to MemTest86. You’ll need to set your USB drive as the primary boot device in the BIOS.

MemTest86 create bootable usb screenshot

Once in MemTest, you can press anything, and it’ll automatically run a detailed memory test after about ten seconds. This may take a while, but by the end, you’ll know whether there are errors in your memory.

FYI: Learn how to fix the “Memory integrity is off” Windows error.

Physically Checking the RAM

How do you solve these errors that were turned up when you checked the RAM health on your Windows machine? Replacing the RAM is obviously the extreme option, but it’s also worth checking to see that it’s properly slotted into your PC.

Try removing the RAM sticks from your PC one by one and running MemTest each time to see whether the errors disappear, to work out which stick (or which slot) was causing the problems. The paid version of MemTest86 will automatically tell you which DIMM (or DIMMs) is faulty.

RGB RAM and a CPU cooler pump
Image source: Unsplash

If you find that errors pop up each time you have a certain stick in, it’s a problem with that stick. If there are problems each time there’s a RAM stick in a certain slot, then that slot could be the issue, at which point you could be looking at a motherboard replacement.

How to Keep RAM Healthy

As with many components in your PC, the best way to keep your RAM healthy is to keep it cool. RAM doesn’t get as hot as your CPU or GPU, but it still generates its own heat, and you want to make sure you have optimized the intake/exhaust fans and airflow on your PC to cool it down. You could even look into a dedicated RAM heatsink if your DIMMs don’t have one already.

Additionally, if you’re thinking of overclocking your RAM, it’s worth knowing that the gains are typically smaller than overclocking your CPU or GPU, and it can shorten the life of your RAM. Instead, if you have an XMP or EXPO profile in your BIOS, you should enable that.

Encountering RAM errors can be annoying. You may need to investigate it further – or worse, replace your RAM completely. But it’s still good to know how to check RAM health on your Windows machine. Once you’ve resolved the issue, you can benchmark your CPU to make sure it’s running as it should, or check the health of your hard drive if you’re facing frequent Windows corruption or file access issues.

Image credit: Unsplash. All screenshots by Tanveer Singh.

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Tanveer Singh
Tanveer Singh - Staff Writer

After a 7-year corporate stint, Tanveer found his love for writing and tech too much to resist. An MBA in Marketing and the owner of a PC building business, he writes on PC hardware, technology, video games, and Windows. When not scouring the web for ideas, he can be found building PCs, watching anime, or playing Smash Karts on his RTX 3080 (sigh).