Blue Screen of Death (BSOD)

Reading the blue screen

When a blue screen appears, note two things:

• Stop code — a short phrase like CRITICAL_PROCESS_DIED or IRQL_NOT_LESS_OR_EQUAL displayed near the bottom. This is your best clue.
• What failed — sometimes a file name appears (like nvlddmkm.sys for NVIDIA drivers or ntfs.sys for file system issues). If you see a .sys file, it usually points to a driver.

Windows also generates a QR code on the blue screen. Scanning it with your phone takes you to a Microsoft support page for that specific error.

Quick fixes to try first

1. Restart normally. If the blue screen only happened once, a restart may be all you need. Windows installs pending fixes during restart.
2. Undo recent changes. Think about what changed right before the blue screens started — a new driver, a Windows update, new software, or new hardware. Undoing that change often fixes it.
3. Boot into Safe Mode if you can't get to the desktop. Hold Shift while clicking Restart from the lock screen, then go to Troubleshoot > Advanced options > Startup Settings > Restart and press 4 for Safe Mode. See our Safe Mode guide for full steps.

Roll back a recent driver

If the blue screen started after a driver update (especially GPU drivers):

1. Right-click the Start button and choose Device Manager
2. Expand the device category (e.g., Display adapters)
3. Right-click the device and select Properties
4. Go to the Driver tab and click Roll Back Driver
5. If the button is grayed out, the previous driver is no longer available — you'll need to download an older version from the manufacturer's website

Uninstall a recent Windows update

1. Open Settings > Windows Update > Update history
2. Scroll down and click Uninstall updates
3. Find the most recent update, select it, and click Uninstall
4. Restart your PC

Check your memory (RAM)

Faulty RAM is a common cause of repeated blue screens, especially with stop codes like MEMORY_MANAGEMENT or PAGE_FAULT_IN_NONPAGED_AREA.

1. Press Win + R, type mdsched.exe, and press Enter
2. Choose Restart now and check for problems
3. Your PC will restart and run a memory test. This takes several minutes.
4. After the test finishes, Windows boots normally. Check the results by searching for Event Viewer, going to Windows Logs > System, and looking for entries from MemoryDiagnostics-Results

If errors are found, one or more RAM sticks may be failing and should be replaced.

Check your disk

File system corruption can also cause blue screens:

1. Open Command Prompt as administrator (search for cmd, right-click, Run as administrator)
2. Run chkdsk C: /f /r and press Y to schedule it for the next restart
3. Restart your PC. The disk check runs before Windows loads.

Common stop codes and what they mean

• CRITICAL_PROCESS_DIED — a core Windows process crashed. Often caused by corrupted system files or a bad driver. Run sfc /scannow in an admin Command Prompt.
• IRQL_NOT_LESS_OR_EQUAL — a driver tried to access memory it shouldn't have. Usually a faulty or incompatible driver.
• SYSTEM_THREAD_EXCEPTION_NOT_HANDLED — a driver crashed. The file name on the screen tells you which one.
• KERNEL_SECURITY_CHECK_FAILURE — memory corruption. Could be a driver issue or bad RAM.
• MEMORY_MANAGEMENT — often points to failing RAM. Run the memory diagnostic.
• PAGE_FAULT_IN_NONPAGED_AREA — a process tried to access memory that wasn't there. Can be RAM, driver, or disk related.
• DRIVER_IRQL_NOT_LESS_OR_EQUAL — almost always a specific driver. The file name tells you which.

When it's hardware vs software

Likely software: Blue screens started after an update, new driver, or new app. Blue screens only happen during a specific activity. Stop code points to a named .sys file.

Likely hardware: Blue screens are random and don't follow a pattern. Memory diagnostic finds errors. Blue screens happen in Safe Mode (which doesn't load third-party drivers). You've heard unusual clicking, buzzing, or the machine overheats before crashing.