Memory Diagnostic runs at boot before Windows loads — save all work and close apps. A failing test usually means faulty RAM or unstable overclock; repeated errors warrant hardware replacement.
What you will achieve
Test system RAM with the built-in Windows Memory Diagnostic tool — schedule a reboot test, read results, and decide whether bad memory explains random crashes or blue screens.
1) Launch Windows Memory Diagnostic
- Search Start for Windows Memory Diagnostic or run
mdsched.exe. - Choose Restart now and check for problems (recommended) or schedule on next boot.
- The PC reboots into the memory test environment automatically.
2) Select test pass level
At the blue memory test screen, press F1 for options:
- Basic — one pass, fastest, least thorough.
- Standard — default; good for most troubleshooting.
- Extended — many passes, hours on large RAM — use when Standard passes but crashes continue.
Press F10 to apply and start. Progress bar and pass count display on screen.
3) Read results after reboot
Windows normally returns to the desktop when tests finish. To view results:
- Open Event Viewer (Win + X).
- Go to Windows Logs → System.
- Filter current log → Event sources: MemoryDiagnostics-Results.
- Event ID 1201 (passed) or errors describing failing addresses.
Alternatively search Start for Performance Monitor, open Reports → System → System Diagnostics — memory diagnostic summary may appear in recent reports.
4) If memory fails
- Power off, reseat RAM modules; test one stick at a time in the recommended slot.
- Disable XMP/EXPO overclock in UEFI and retest.
- Update BIOS and chipset drivers from the motherboard maker.
- Replace modules that fail consistently in known-good slots.
5) Complement with other crash tools
Memory Diagnostic does not test GPU VRAM or CPU cache exhaustively. Pair results with minidump analysis from blue screen guides and driver updates. Boot Safe Mode if crashes prevent scheduling the test — our Safe Mode guide covers entry on Windows 11.