One of the most common reasons a PC may refuse to start or experience instability issues can be tried to one of its most utilized components: the Memory Modules aka RAM.  RAM related issues manifest in different ways, including but not limited to:

• Applications and Games freezing, hanging, or crashing
• Random full system restarts
• Stop code/Stop screens, aka BSOD (Blue Screen of Death)
• No signal to the Monitor
• Not completing boot into Windows

If you are looking for information on how to identify a potential RAM issue, please check out the guide below:

Identifying RAM Issues

Once you have identified a RAM issue and can get the PC to complete POST (Power-on Self Test) and with a signal to the monitor, this guide will help in confirming the issue.

Memory Testing Software

There are various tools available that can help test and confirm a RAM related issue, including some built into Windows itself.  For this guide, we'll cover three common tools depending on if you can log-in to your Windows account.

Windows Memory Diagnostic (mdsched)

Windows Memory Diagnostic, also known by its command name mdsched is a utility included with the Windows Operating System and Recovery Environment that can test and identify a PC's RAM for hardware-related errors.  The easiest way to run this tool is to search for either Windows Memory Diagnostic or the command name mdsched in the Start Menu's search bar, then run the program as shown below:

Once you run the program, you will be prompted to restart your PC in order to begin the test.

If you are unable to load into Windows, you can still run the tool either from the Windows Recovery Environment or from a Windows USB installer.  For instructions on how to access the Recovery Environment or to create a bootable Windows USB, please see the guides below:

• How to open Windows Recovery Environment (WinRE)
• How to Install Windows 11

Once you are in the Recovery Environment or loaded from a bootable Windows USB, choose the Command Prompt option found in Troubleshooting > Advanced Options and run the command mdsched to start the test.

Once the PC has loaded into the Windows Memory Diagnostic Tool window, the test will run automatically until completion.  We do recommend checking in with the test from time to time in case it freezes or you get a message stating that a hardware error has been found.  Once the test completes, the system will automatically restart and a pass or fail message will be stored in the Event Viewer.

To find the result, search for the Event Viewer program in your Start Menu, then on the right side you will need to select Windows Logs > System and look for an Information item with the MemoryDiagnostics-Results source as shown above.  These results may not be available when using Windows Recovery Environment.

MemTest86

Considered by many in the IT field to be the go-to tool for checking memory related issues, MemTest86 is a powerful tool that can be used without needing to boot int Windows directly.  This makes the tool ideal for situations where a memory issue may be preventing you from logging in or if you are running into issues reinstalling Windows.

To get started, you'll need the following:

• A USB Flash Drive
• A working PC running Windows
  • This can be done on other operating systems, however for this test we will only cover the Windows operating system.

MemTest86 can be downloaded for free from the link below:

PassMark Software - MemTest86 Download

Once downloaded, extract the contents of the .zip file to a folder in your desktop and insert the target flash drive into the PC.

Run the imageUSB application included in the extracted folder, then do the following:

• Select the target USB drive from the list of available drives (Step 1)
• Make sure that the option Write image to USB Drive is selected and that Fast Image Verification is enabled (Step 2)
• If the .img file is not already present, click the Browse button and select the .img file in the extracted folder (Step 3)
• Click the Write button and follow the prompts given by the program (Step 4)

Once the write completes it is ready for use.  Remove the USB drive from the system and plug it in to the computer experiencing the memory issues.  Once you see the motherboard splash screen, access the Boot Menu through one of the following options:

• If your Splash Screen specifically notes a Boot Menu, press the associated key and select the flash drive as your boot option.
• If your Splash Screen does not note a Boot Menu, press Delete or F2 to enter the BIOS and check for either a Boot Menu or Boot Override option.

For more information on alternative booting, please refer to your motherboard user's manual.

MemTest86 will automatically start after a few seconds and will create a report on the flash drive once the test completes.  This test can also identify errors on a per-module basis which can be useful if your PC has more than 2 memory modules installed.  For more information, please refer to the User Guide document included in the downloaded file.

OCCT

If you are able to boot into Windows, OCCT is a powerful stability testing tool that includes a number of targeted hardware tests that you can mix and match for many test scenarios.  You can download OCCT for free using the link below:

OCBASE - OCCT

For the purposes of this test, select the Memory test from the list of options and run it with the default settings.  If OCCT detects any memory errors, these will be logged on the program itself.

I confirmed a hardware error, what do I do now?

Once a RAM error is confirmed, it's going to require replacement of the module to resolve the issue.  If you are using a pre-built system, the system integrator (i.e. NZXT) may be able to facilitate a replacement while the PC is still under a system warranty.  If you are outside of the system warranty, it si recommended to reach out to the manufacturer of the RAM module directly for replacement support questions.