Windows Memory Diagnostic — RAM Test Results and Error Interpretation

Run and interpret Windows Memory Diagnostic (mdsched.exe) results, understand RAM error types, and troubleshoot faulty memory causing BSODs and crashes. This guide covers everything you need to know about this topic, including common causes, step-by-step solutions, and answers to frequently asked questions.

Here are the key things to understand: Windows Memory Diagnostic (mdsched.exe) tests RAM for hardware errors at boot time. Tests run outside Windows to access all RAM regions including those used by the OS. Results appear in Event Viewer > Windows Logs > System > source 'MemoryDiagnostics-Results'. Standard test runs multiple passes; Extended test adds more patterns but takes hours. Faulty RAM causes random BSODs, application crashes, file corruption, and boot failures. Understanding these fundamentals will help you diagnose and resolve this issue more effectively.

The most common reasons this occurs include: Physical RAM module failure due to age, heat damage, or manufacturing defect. RAM not fully seated in the DIMM slot causing intermittent contact. Incompatible RAM modules mixed together (different speeds, voltages, or timings). XMP/DOCP profile setting RAM speed beyond the module's stable limit. Motherboard memory controller issue affecting specific DIMM slots. Identifying the root cause is the first step toward finding the right solution.

To resolve this, follow these recommended steps: Run Windows Memory Diagnostic: mdsched.exe > Restart now and check for problems. Press F1 during the test to switch to Extended test mode for thorough testing. Check results after reboot: Event Viewer > Windows Logs > System > MemoryDiagnostics-Results. For more thorough testing: download and run MemTest86 from a USB drive (runs for hours). If errors found: test each RAM stick individually to isolate the faulty module. Try disabling XMP/DOCP in BIOS to run RAM at default (JEDEC) speed and retest. If these steps do not resolve the issue, consider consulting additional resources or a qualified professional.

This article is part of our Windows Error Codes collection on Error Codes Wiki. We provide comprehensive, up-to-date information to help you find solutions quickly.