When your PC starts stuttering or freezing up randomly, it’s time to put on your detective hat and examine. Testing your RAM for memory errors should be the first step on this journey, as bad memory is the most common cause of such problems.
There are various methods (and tools) for testing RAM, from built-in Windows utilities to third-party software. We’ll go over each option in this detailed guide to help you choose the best method.

Should You Test Memory With or Without Pre-Booting?
For many years it was believed that computer memory needed to be tested with a pre-boot tool. This is because in old systems the memory was quite limited. It was not uncommon for the operating system to account for the majority of system resources, with very little memory to test.
In modern computers this is no longer a problem. PCs have more RAM than ever, and the operating system only uses a small amount. This makes memory testing tools that work without pre-boot just as good as traditional testing software.
Additionally, the test algorithms used by the prestart tools are not as accurate in simulating real-world usage patterns. While these algorithms can track down big logic problems, many smaller errors can go undetected. For this reason, it is recommended that you also test your memory with an application that can run on Windows.
Test Your RAM With the Windows Memory Diagnostic Tool
The simplest tool you can get is the Windows Memory Diagnostic Tool, as it is built into Windows. No need to create a bootable USB stick or download an application.
It is also good to detect glaring memory errors and will help you detect a faulty RAM module with little effort. The only downside is that the tool is quite old and doesn’t work as well for finding more subtle memory errors.
- To run the Windows Memory Diagnostic tool, type memory diagnostic in the search box and press Enter.
- When you run the application, you will see a message with two options. You can schedule a scan the next time you restart your computer, or you can choose to “restart now” and check for problems.

- After restarting the PC, the Windows Memory Diagnostic Tool starts automatically. Your RAM will undergo various tests and the status will be updated if errors are found.

- Once the test is complete, the computer should start normally. According to the tool, you should receive a message about the test results, but this rarely appears in practice. To see the results, you must search for the message in the Event Viewer. Right-click the Start button and select Event Viewer.

- The Event Viewer has a complicated user interface. Displays logs of all actions performed on the computer, including system tasks. First, go to Windows Logs> System in the list on the left.

- This will show a list of all system events, but finding the right one manually is an uphill task. Select Find… from the actions on the right.
- Enter MemoryDiagnostics to locate the records of the testing event. Close the box to view the details in the middle pane.

Related: How to Fix “ There was a problem starting logilda.dll ” in Windows 10
Use Passmark’s MemTest86 To Check Your RAM
The built-in Windows utility isn’t exactly the best RAM testing tool out there. It is quite old. While it can catch basic errors, many advanced problems can often go undetected.
To comprehensively test your memory and rule out problems, we recommend MemTest86. A well-known tool, a pre-boot application, that thoroughly checks your RAM for errors.
- Head to the official website to download the free version of the software.

- Since the application has to boot from a USB stick, the setup is actually an image writing program. Use it to prepare a USB drive with MemTest86.

- If you restart your computer now, MemTest86 will boot from USB. You can press any key on the home screen to stop the startup process and set the options first. However, we recommend leaving all options with their default values on your first try.

- After this MemTest86 will start running tests on the RAM. You can view the progress on your screen, including the number of errors found.
- Upon completion of the process, you’ll get a Result summary outlining the main issues discovered by the tests.

- You’ll be prompted to save an HTML report on the USB stick. Press y to do so.

- This HTML report can be accessed after your computer has started normally and is on the USB stick. It includes a more detailed look at the tests and the information that resulted from them.

Is MemTest86+ Different?
You may have heard of the software under a slightly different name: MemTest86 +. It’s just another branch of the same app with mostly similar functionality. In general, you shouldn’t use both. Pick one of these versions and go with it.

Test Without Pre-Booting With HCI Design’s MemTest
All the apps we’ve seen so far test memory without the operating system running. This used to be the standard method because Windows itself could use a large part of the available memory and prevent the software from testing all memory.
Today, storage capacities far exceed operating system requirements. Also, pre-boot tests are poor at simulating actual RAM usage and can often miss critical errors.
For this reason, it is recommended that you test your RAM with a test tool that can run alongside Windows. And MemTest by HCI Design is one of the best free apps for that.
- To begin, download the MemTest from HCI Design’s website.
- No installation is required. Simply unzip the folder you have downloaded and run the application.

- Now you can enter the amount of RAM you want to test. By default, all unused RAM is tested, which is the best option. Close any other running programs before clicking the Start Test button.

- As the test progressed, the application will display the coverage percentage and the number of errors detected below. It is recommended to let the application run for a few hours until at least 100% coverage is achieved.
Fast Memory Check With RAM Test
MemTest from HCI Design is great, but a little slow. If you are looking for faster inOS RAM tests, consider Karhu Software’s RAM test.
Since this is a premium application, you must purchase a license to use it. It is the best option for those who need to test multiple PCs on a regular basis, as the high speed really helps in this case.
- To download the RAM test, buy a license from Karhu Software’s website.

- When you run the application, you will get a window like this, similar to the previous tool but much more detailed. You can see the amount of free memory, the total memory, and the number of threads that will run in parallel.
- When the RAM test is running, you can see the coverage and number of errors below. Ideally, you should let the application run for many hours to find any errors.
How to Diagnose RAM Problems On Your Computer
If you encounter unexpected errors while your computer is running, the problem may be due to low memory. After all, running applications load into RAM while they are running, and errors in memory sectors can affect their proper functioning.
Fortunately, checking the status of your RAM is not a difficult or highly technical task. You can test your computer’s memory with bootable and non-bootable tools and quickly identify the source of your problems.
We recommend that you use at least one tool in each category, as all types of memory errors are fully resolved with it. And if your memory turns out to be faulty, the only solution is to replace it with the correct type of memory.
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