What is the Windows blue screen (BSOD)?

The blue screen, also known as the Blue Screen of Death (BSOD), is an error message that appears when Windows runs into a critical system error. Windows 10 and 11 also show a sad face and a QR code.

Common causes

Driver problems

The most common cause. Outdated or incompatible drivers can lead to crashes.

Faulty hardware

Broken RAM, an overheating processor, a failing hard drive or a failing power supply.

Software conflicts

Programs that conflict with each other or with Windows.

Corrupted system files

Caused by power outages, improper shutdowns or malware.

Common BSOD error codes

  • CRITICAL_PROCESS_DIED: Essential process stopped
  • SYSTEM_SERVICE_EXCEPTION: Driver or service problem
  • IRQL_NOT_LESS_OR_EQUAL: Memory or driver problem
  • PAGE_FAULT_IN_NONPAGED_AREA: Memory problems
  • KERNEL_DATA_INPAGE_ERROR: Hard drive problem

Step-by-step solutions

Step 1: Boot into Safe Mode

  1. Restart and press F8 repeatedly
  2. Choose 'Troubleshoot' > 'Advanced options' > 'Startup Settings'
  3. Press 4 or F4 for Safe Mode

Step 2: Uninstall recently installed software

Open Control Panel > Programs and uninstall recently added programs.

Step 3: Run System Restore

  1. Search for 'Create a restore point'
  2. Click 'System Restore'
  3. Choose a restore point from before the problems started

Step 4: Repair system files

  1. Open Command Prompt as administrator
  2. Type: sfc /scannow
  3. Then: DISM /Online /Cleanup-Image /RestoreHealth

Step 5: Test your memory

Search for 'Windows Memory Diagnostic' and run the test.

Frequently asked questions

Can I lose data because of a blue screen?

A BSOD itself normally doesn't cause loss of saved files. Unsaved work can be lost, though.

My computer keeps showing the same blue screen. What should I do?

Write down the error code, boot into Safe Mode, and try uninstalling recently installed software or running System Restore.

Is a blue screen always a sign of serious problems?

Not necessarily. A one-time BSOD can be a temporary glitch. Recurring BSODs need further investigation.