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How to Diagnose Bad RAM Using Windows Memory Diagnostic Tool

7 min read
Updated: November 2026
Hardware Stress Test

Failing Random Access Memory (RAM) is notoriously difficult to diagnose because it produces chaotic, intermittent errors. One hour a game crashes with an access violation, the next day Windows blue screens with MEMORY_MANAGEMENT, and files saved to your disk end up silently corrupted. Fortunately, Windows has a dedicated pre-boot memory diagnostic tool built in.

Common Symptoms of Faulty RAM

  • Blue Screen Stop Codes: MEMORY_MANAGEMENT (0x0000001A), PAGE_FAULT_IN_NONPAGED_AREA (0x00000050), or BAD_POOL_HEADER.
  • Random App Crashes: Chrome or Edge tabs crashing with "STATUS_ACCESS_VIOLATION".
  • Silent File Corruption: Newly downloaded .zip files or installer packages reporting invalid CRC hashes.
  • PC Reboots During Heavy Multitasking: Crashes occur specifically when opening many browser tabs or memory-intensive rendering jobs.

Step 1: Launch Windows Memory Diagnostic (mdsched)

Save any unsaved work in open documents before beginning, as the test requires a reboot:

Run Command
mdsched.exe

Press Win + R, enter mdsched.exe, and click OK.

Step 2: Choose When to Restart

A dialog box will appear presenting two options:

  1. Restart now and check for problems (recommended): Immediately reboots the machine directly into the memory diagnostic tester.
  2. Check for problems the next time I start my computer: Queues the test for your next manual system restart.

Step 3: Configuring Pre-Boot Test Matrices

Once your PC reboots, the screen turns blue and displays the Windows Memory Diagnostic Tool running Pass 1 of 2.

By default, it executes the Standard test suite. For thorough testing, press F1 to enter Options:

1

Test Mix

Basic: MATS+, INVC, SCHCKR (Light check).
Standard: Adds LRAND, Stride6, WCHCKR, ERAND (Recommended for general instability).
Extended: Tests WSCHCKR, Stride38, CHCKR8, Rand_16 (Takes several hours, best for deep hardware certification).

2

Cache Mode

Set Cache to Default or Off. Disabling cache forces the CPU to read and write directly to physical DDR memory pins rather than CPU L3 cache lines.

3

Pass Count

Set Pass count to 2 or 4. Intermittent thermal memory faults often only show up on subsequent passes once RAM chips heat up.

Press F10 to apply settings and start the test suite.

Step 4: How to Find the Test Results in Event Viewer

After the diagnostic finishes, Windows restarts and loads your normal desktop. The desktop notification often disappears quickly, but the full hardware log is permanently preserved in Event Viewer:

  1. Open Event Viewer (Win + R > eventvwr.msc).
  2. Navigate to Windows Logs > System.
  3. Click Find... in the right-hand panel and search for: MemoryDiagnostics-Results.
Event IDs to Look For
• Event ID 1101: Windows Memory Diagnostic completed successfully and found NO memory errors.
• Event ID 1102: Hardware errors detected! Your RAM has bad sectors or failing timing registers.

What to Do If Hardware Errors Are Found

If errors are flagged, take these physical troubleshooting steps:

  1. Disable XMP / EXPO in BIOS: High-frequency memory profiles (e.g. 6000MHz+) may be unstable on your motherboard. Revert to standard JEDEC frequencies.
  2. Isolate the Faulty Stick: If you have two or four RAM sticks, remove all but one and run mdsched again. Test each stick individually to pinpoint the exact defective module.
  3. Reseat the RAM: Dust buildup or unseated clips can cause poor pin contact. Clean the gold contacts with isopropyl alcohol.