A blue screen is Windows stopping the PC on purpose, because continuing could damage data. It is annoying, but it is also the most honest diagnosis the system can give you: it names an error code and often the file that failed. (In recent Windows 11 versions the screen may be black instead of blue; the meaning is the same.)
The same code and file every time
Usually a driver or a program: reinstall the driver, remove the last update or the overclock.
A different code every time
Usually hardware: memory, overheating, power supply or an unstable overclock. Test them one by one.
Photograph the screen or write down the code and the file name: this is the most useful information.
1. First, collect the evidence
- Photograph the screen or write down the stop code (for example VIDEO_TDR_FAILURE) and the file name in brackets (for example nvlddmkm.sys).
- Turn off automatic restart so you have time to read it: Win+R → sysdm.cpl → Advanced → Startup and Recovery → Settings → untick Automatically restart. Keep “Small memory dump” selected.
- After a reboot, open BlueScreenView: it reads the saved dump files and shows which driver was involved in each crash.
- Also check Event Viewer: Win+X → Event Viewer → Windows Logs → System, and look for BugCheck and Kernel-Power 41 around the time of the crash.
2. What the most common codes mean
| Code or file | Usual cause | What to do |
|---|---|---|
| VIDEO_TDR_FAILURE, nvlddmkm.sys, atikmpag.sys | Graphics driver, or an unstable GPU overclock or undervolt | Reinstall the driver cleanly with DDU (drivers guide), reset any tuning (GPU tuning guide) |
| MEMORY_MANAGEMENT, PAGE_FAULT_IN_NONPAGED_AREA, IRQL_NOT_LESS_OR_EQUAL | Memory (RAM) or a faulty driver | Test with MemTest86; try without XMP/EXPO (XMP guide); reseat the sticks |
| WHEA_UNCORRECTABLE_ERROR, CLOCK_WATCHDOG_TIMEOUT | CPU, power, overheating or an unstable overclock | Load BIOS defaults, check temperatures, update BIOS (BIOS guide) |
| DPC_WATCHDOG_VIOLATION | SSD driver or firmware, a slow disk | Update the storage driver and SSD firmware, check the disk in CrystalDiskInfo |
| INACCESSIBLE_BOOT_DEVICE | Windows cannot find the system disk | Check the disk in BIOS, the SATA/NVMe mode, cables; after a BIOS update load defaults again |
| CRITICAL_PROCESS_DIED, SYSTEM_SERVICE_EXCEPTION, KERNEL_SECURITY_CHECK_FAILURE | Damaged system files, drivers, sometimes memory or disk | Run sfc and DISM (step 3), update drivers, test memory |
The code alone is a hint, not a verdict: the same code can have several causes. The pattern matters more, see the figure above.
3. Step by step: from simple to complex
- Undo what changed last: a new driver, a Windows update, a new program, an overclock, XMP, a new part. A blue screen that started “recently” usually has a recent cause.
- Boot in Safe Mode if Windows does not load: hold Shift and click Restart, or interrupt the boot three times; then Troubleshoot → Advanced options → Startup settings → Safe Mode.
- Repair system files. Open Terminal (Admin) and run sfc /scannow, then DISM /Online /Cleanup-Image /RestoreHealth, and reboot.
- Update or cleanly reinstall drivers: graphics first, then chipset, network and storage. See the drivers guide.
- Check temperatures with HWiNFO: above about 90 °C on the processor or 85 °C on the graphics card points to cooling. Clean the dust (cleaning guide) and renew the paste (thermal paste guide).
- Test the memory: run MemTest86 for several passes, or one stick at a time if you have two. Any error means a faulty stick, the wrong settings or a bad slot. The other tests are in our stress test article.
- Check the disk: CrystalDiskInfo should show “Good”; reallocated or pending sectors mean the drive is dying. Back up first.
- Update the BIOS only if the maker lists a fix for your problem (BIOS guide), and make sure the power supply is not overloaded.
- Reinstall Windows as the last software step (clean install guide). If the blue screens remain on a clean system, the cause is hardware.
4. When to take the PC to a service
- MemTest86 shows errors even on a single stick in different slots.
- Blue screens continue on a clean Windows with default BIOS settings.
- The PC restarts on its own under load without any code: this often points to the power supply or overheating.
- The disk reports bad sectors.
If you do not want to look for the cause yourself, bring the PC with the code or a photo of the screen: this will save diagnostic time. And if you are planning a new build with tested parts, use our PC configurator.