If you want a free RAM test for Windows, start with Windows Memory Diagnostic. It restarts the PC and checks memory before you return to Windows. A browser page that reports memory usage does not perform the same test. If Windows cannot start or you need a second check, use a compatible bootable MemTest86 USB.
Run a free RAM test and find the result
- Save your work, open Start, and search for
mdsched. - Choose the restart option when you can leave the computer out of use. The diagnostic runs during the restart.
- After Windows loads, look for the result notification. If you missed it, open Event Viewer and look for the memory diagnostic result from the time of the test. Follow Microsoft’s Memory Diagnostic and Event Viewer instructions. A reboot on its own tells you nothing about the result.
When a bootable USB is the better choice
Check PassMark’s platform and boot instructions before downloading MemTest86. Use an empty USB drive, since preparing it overwrites its contents. Confirm the target drive before writing, then choose the USB from your PC’s boot menu. Record the reported error count and the settings under which you ran the test. PassMark provides example screens and a result summary.
What a RAM test error means
A reported memory error is evidence of instability under the tested settings. It does not identify the exact failed part by itself. A memory profile, a module, a slot or another part of the memory path can be involved. Back up important files and consult the PC or motherboard maker’s guidance before changing hardware or firmware settings.
For example, if errors began after enabling an XMP memory profile, record the settings and repeat the test at the manufacturer’s standard settings if you know how to change them safely. If errors persist, bring the results to support. A clean run means the tool found no errors in that run. Continue investigating if crashes recur. See PassMark’s error interpretation guide.
Record the date, the test tool and the settings in use. If you change a memory profile before retesting, keep the original result and compare runs under the same workload where practical. A record of which settings changed is more useful for troubleshooting than a single error screenshot without context.
If the machine has been unstable since a memory upgrade, write down what changed and check the computer or motherboard manual for the supported configuration. Save work before rerunning the RAM test. Keep the result with the date and the configuration you tested so you can compare runs after changing one thing at a time. If you contact support, include whether the machine was using its factory memory or an upgrade when the error occurred. A clean result makes a memory problem harder to reproduce, but it does not explain a crash by itself. If the same app still fails, keep its error message and investigate that app, driver or storage separately.
If the memory test result is missing
Check Event Viewer for the time of the reboot and confirm that you are reading the latest test. If the machine restarted unexpectedly or you interrupted the test, run it again when you can leave it uninterrupted. Treat a run with no recorded result as inconclusive. For a support request, include the diagnostic used, the time, and the exact error text if one appeared.
Our take: Save the result before buying replacement RAM. Start with the built-in test and use a bootable check when the problem persists or Windows will not start. This guide uses Microsoft and PassMark documentation. See Fix Guides and the backup and sync hub for related help.
