Blue screen (BSOD) – causes, error codes and fixes

The Blue Screen of Death (BSOD) is probably the most alarming message a Windows user can see. The computer suddenly crashes, shows a screen with a cryptic error and restarts – often taking unsaved work with it. In this guide you will learn what causes a BSOD, how to diagnose it from the stop code and how to fix it.

What is a blue screen (BSOD)?

A BSOD is how Windows tells you it has hit a critical error it cannot recover from. Instead of carrying on and risking damage to your data or hardware, Windows stops everything and shows a screen with diagnostic information.

What does a BSOD look like?

Windows 10 and older Windows 11 versions: A blue screen with a sad face :( and the message:

"Your PC ran into a problem and needs to restart. We're just collecting some error info, and then we'll restart for you."
Stop code: DRIVER_IRQL_NOT_LESS_OR_EQUAL

Current Windows 11 versions (since 2025): The screen is black instead of blue and has no sad face, but it shows the same stop code – everything in this guide still applies.

The most common BSOD stop codes and what they mean

1. DRIVER_IRQL_NOT_LESS_OR_EQUAL

Cause: A faulty or incompatible driver (most often for the graphics card, Wi-Fi or Bluetooth)

Fix:

• Update your drivers (Device Manager > right-click the device > Update driver)
• If it started after installing a new driver, roll back to the previous version
• Run Driver Verifier to identify the problem driver

2. SYSTEM_SERVICE_EXCEPTION

Cause: Corrupted system files or problem drivers

Fix:

• Run an SFC scan: sfc /scannow in an administrator terminal
• DISM repair: DISM /Online /Cleanup-Image /RestoreHealth
• Install all available updates through Windows Update

3. PAGE_FAULT_IN_NONPAGED_AREA

Cause: Problems with RAM or drivers

Fix:

• Test your RAM with Windows Memory Diagnostic or MemTest86
• Remove and reseat the RAM modules
• Test with one RAM module at a time if you have several

4. KERNEL_DATA_INPAGE_ERROR

Cause: Problems with the hard drive or RAM

Fix:

• Run CHKDSK: chkdsk C: /f /r
• Check the drive’s SMART status (CrystalDiskInfo)
• Test your RAM
• If the HDD is more than 5 years old, consider replacing it

5. NTFS_FILE_SYSTEM

Cause: A corrupted NTFS file system or HDD problems

Fix:

• Run CHKDSK with the repair options
• Check system files with SFC
• Check the drive with CrystalDiskInfo

6. CRITICAL_PROCESS_DIED

Cause: A critical Windows process was terminated (corrupted system, malware)

Fix:

• SFC and DISM checks
• A full antivirus scan
• Windows Update
• If nothing helps: a clean Windows installation

7. UNEXPECTED_STORE_EXCEPTION

Cause: Storage driver problems or corrupted system files

Fix:

• Update the chipset and storage drivers
• Repair with SFC and DISM
• Turn off Fast Startup (Control Panel > Power Options)

8. VIDEO_TDR_FAILURE

Cause: A graphics card or graphics driver problem

Fix:

• Update the GPU drivers (NVIDIA App, AMD Software: Adrenalin Edition)
• Use DDU (Display Driver Uninstaller) for a clean driver reinstall
• Check the GPU temperature (MSI Afterburner)
• Return to default clocks if you overclocked the graphics card

9. MEMORY_MANAGEMENT

Cause: Faulty RAM or memory management problems

Fix:

• Windows Memory Diagnostic or MemTest86
• Remove and reseat the RAM modules
• Test each RAM module on its own
• Try a different RAM slot

10. DPC_WATCHDOG_VIOLATION

Cause: Outdated or incompatible SSD firmware or drivers

Fix:

• Update the SSD firmware (Samsung Magician, Crucial Storage Executive)
• Update the chipset drivers
• Try a different SATA cable or port

General causes of a BSOD

1. Faulty drivers

The most common cause. Outdated, corrupted or incompatible drivers (graphics, Wi-Fi, audio) can crash the system.

2. Hardware problems

• Faulty RAM (the most common)
• A failing hard drive or SSD
• An overheating CPU or graphics card
• A faulty graphics card or motherboard

3. Corrupted system files

Windows system files can be damaged by viruses, a failed Windows Update or an unclean shutdown.

4. Overclocking

An unstable overclock of the CPU, graphics card or RAM can crash the system.

5. Viruses and malware

Malware can damage system files or drivers.

Fixes you can try yourself

Step 1: note the error code

When the BSOD appears, write down:

• The stop code (e.g. “DRIVER_IRQL_NOT_LESS_OR_EQUAL”)
• The failing file (the file that caused the error), if shown (e.g. “nvlddmkm.sys”)

Step 2: look at the minidump files

Windows saves dump files after a BSOD so it can be analysed:

1. Download BlueScreenView (a free tool from NirSoft)
2. Run BlueScreenView – it loads the dump files automatically
3. Look at the error code and the problem driver (highlighted in red)

Step 3: update drivers

1. Device Manager (Win + X > Device Manager)
2. Look for devices with a yellow exclamation mark, or ones you suspect
3. Right-click > Update driver > Search automatically for drivers
4. Pay special attention to graphics, chipset, Wi-Fi and audio drivers

Step 4: run SFC and DISM

1. Open an administrator terminal: Win + X > Terminal (Admin)
2. Type sfc /scannow and press Enter (takes 15–30 min)
3. Then run: DISM /Online /Cleanup-Image /RestoreHealth
4. Restart the computer

Step 5: test your RAM

1. Win + R > type mdsched.exe
2. Choose “Restart now and check for problems”
3. The computer restarts and tests the RAM (takes 20–60 min)
4. If the tool finds errors, the RAM is faulty and needs replacing

Step 6: check the hard drive

1. Open an administrator terminal
2. Type: chkdsk C: /f /r
3. Press Y to schedule the check for the next restart
4. Restart the computer – the disk check runs automatically (takes 1–3 hours)

Step 7: check temperatures

1. Download HWMonitor or Core Temp
2. Check the CPU and graphics card temperatures
3. A CPU above 85 °C or a graphics card above 90 °C means overheating!
4. The fix: dust cleaning and new thermal paste (at a service centre)

Step 8: troubleshoot in Safe Mode

If the BSOD keeps coming back:

1. Start Safe Mode: Settings > System > Recovery > Advanced startup > Restart now
2. Troubleshoot > Advanced options > Startup Settings > Restart
3. Press F4 for Safe Mode
4. In Safe Mode, uninstall the most recently installed drivers or programs

When should you call an IT technician?

• The BSOD appears every day or several times a day
• You have tried everything above without success
• You suspect a hardware fault (RAM, motherboard, HDD)
• The computer cannot start Windows (BSOD at startup)
• You are losing important data because of the crashes
• You do not have the technical knowledge to diagnose it
• The BSOD started after a hardware upgrade

Preventing a BSOD

1. Keep drivers up to date

Update your drivers every 3–6 months, especially graphics and chipset.

2. Windows Update

Keep Windows updated – Microsoft regularly fixes bugs that cause crashes.

3. Look after your equipment

• Clean out dust every 6 months
• Watch the temperatures
• Use a UPS for stable power

4. A good antivirus

Malware can cause a BSOD – keep your antivirus up to date.

5. Do not overclock (unless you know what you are doing)

An unstable overclock is a common cause of crashes.

6. Back up your data

A BSOD can corrupt data – regular backups are a must!

Conclusion

A blue screen is a serious problem that needs a diagnosis. You can fix some cases yourself (updating drivers, an SFC scan, a RAM test), but often it needs professional help – especially with hardware faults. The key is to act quickly, write down the error code and try the basic steps before the problem gets worse.

When the cause is software (drivers, corrupted system files, malware), Perfect Light in Zagreb can help with diagnostics, system repair or a clean Windows installation. If you suspect a faulty component, contact an authorised service centre.