A blue screen error appears when Windows meets a fault so serious that it cannot keep running safely. The screen turns blue, shows a sad face on newer versions, collects some data, and restarts. The formal name is a stop error, and many people call it the BSOD.
It looks scary but it is a protective stop, not proof that the computer is finished. The most important detail is the stop code or the line in capital letters on the screen. This page shows how to read it, which fixes to try first using only built-in Windows tools, and when a blue screen suggests failing hardware.
Common causes
1Faulty or new driver
How to tellStarted after installing a driver or Windows update, and the code names a driver file
What fixes itRoll back or remove the driver in Safe Mode or Device Manager
2Failing memory (RAM)
How to tellRandom crashes, different codes each time, crashes under load
What fixes itReseat the RAM and run the Windows Memory Diagnostic
3Corrupted system files
How to tellCrashes with file or boot related codes, odd behaviour before it
What fixes itRun SFC and DISM from an administrator window
4Disk errors or a failing drive
How to tellSlow start, clicking sounds on an old drive, codes about inaccessible boot device
What fixes itBack up data at once and check the disk; replace the drive if failing
5Overheating or dust
How to tellCrash while gaming or heavy work, fan loud, case very hot
What fixes itClean vents and fans and improve airflow; see the fan page
6New hardware or a bad USB device
How to tellCrashed right after plugging in a new device or upgrading a part
What fixes itUnplug the new device and test without it
7Incomplete Windows update
How to tellCrash loop right after an update restarts
What fixes itUninstall the latest update from recovery options
8Overclocking or wrong BIOS settings
How to tellCrashes began after changing speed or power settings in BIOS
What fixes itReset BIOS settings to default
How to fix it, step by step
Write down or photograph the stop code
Read the text near the bottom, such as a stop code line in capital letters, and any file name beside it. Take a photo with your phone if the screen restarts quickly. That one line decides which of the later steps matters most.
Disconnect extra devices and restart
Remove pen drives, printers, external drives, dongles and anything new. Restart the computer. If it starts normally, plug the devices back one by one to find the one that triggers the crash.
Start in Safe Mode if it keeps crashing
If Windows restarts into the blue screen again and again, it usually opens Recovery after a few failed starts. Choose Troubleshoot, Advanced options, Startup Settings, Restart, then press the key for Safe Mode. Safe Mode loads only basic drivers so you can undo changes.
Uninstall the latest update or driver
If the crashes began after an update, go to Settings, Windows Update, Update history, Uninstall updates. For a driver, open Device Manager, double click the device, check the Driver section for a rollback choice. Display and network drivers are the most frequent causes.
Run System File Checker and DISM
Right click Start and open Terminal or Command Prompt as administrator. Type
sfc /scannowand press Enter. When it finishes, runDISM /Online /Cleanup-Image /RestoreHealth. These repair damaged Windows files using official Windows sources and need an internet connection for DISM.Install Windows updates and driver updates
In Windows Update, install pending updates, including optional driver updates if offered. Get chipset, graphics and storage drivers only from your computer maker or the chip maker, never from a download site or a driver fixer tool.
Test the memory
Search for Windows Memory Diagnostic, choose to restart and check now, and let it finish. If errors appear, a RAM module is likely faulty. On a desktop you can switch off, unplug and reseat the sticks. On a laptop with soldered memory, go to service.
Check the disk and free space
Make sure the system drive has some free space. Run
chkdskfrom an administrator window or use the drive check in the drive properties. Back up your files right away if Windows reports disk errors.Use System Restore or reset Windows
In recovery options, try System Restore to return to a date before the problem. If nothing works, Reset this PC with the option to keep your files can rebuild Windows. Back up first, because a reset is a last step.
What a blue screen error means
Windows keeps drivers and hardware under constant watch. When one of them breaks a rule that could corrupt data, Windows halts and shows the blue screen rather than risk damage. It also saves a small dump file that records the cause. So the screen is a safety brake, and the code is its note about why it braked.
You open a game and the screen turns blue with the words Your device ran into a problem and needs to restart and a code that includes VIDEO. That points to the graphics driver, so rolling it back or updating it is the first fix.
Common stop codes and where to look
| Stop code | Usual meaning | Look at first |
|---|---|---|
| WHEA UNCORRECTABLE ERROR | Hardware reported a fault it could not fix | Overheating, CPU or RAM, power |
| VIDEO DXGKRNL FATAL ERROR | Graphics system failed | Graphics driver |
| INACCESSIBLE BOOT DEVICE | Windows cannot read its drive | Drive, cable, recent update |
| MEMORY MANAGEMENT | Memory problem | RAM test |
| CRITICAL PROCESS DIED | A needed system process stopped | System files, drivers |
| IRQL NOT LESS OR EQUAL | A driver touched wrong memory | New driver or device |
Other Windows codes are listed in Windows error codes.
Blue screen error on Windows 10 and Windows 11
Both show a blue screen with a QR code and a stop code, and the fix steps are the same. Windows 11 may also show a black screen instead of blue in some setups, which is only a colour change. Older versions such as Windows 7 show many lines of text instead of a sad face, and the stop code appears near the top. Whichever version you have, note the code, undo recent changes, and repair system files.
When hardware is the cause and what it costs to repair
If different codes appear each time, if the PC crashes even in Safe Mode, or if memory and disk tests fail, the cause is likely hardware. Repair cost depends on which part fails: RAM is usually the cheaper fix, while a drive or motherboard costs more and may need data recovery. If it is a laptop and you cannot open it safely, use a service centre. The laptop not working hub lists more hardware signs, and Windows Update error if the crash follows an update.
Never use cracked Windows, driver fixer tools or registry cleaners. They are a common cause of blue screens and can carry harmful software.
How to prevent blue screens
Keep Windows updated, install drivers only from the maker, keep dust out of the vents, and leave some free disk space. Do not turn the computer off with the power button during an update. Back up important files regularly so a crash never becomes a loss.
Frequently asked questions
What is a blue screen error?
It is a screen Windows shows when it stops because of a serious problem with a driver, memory, disk or system file. It protects your data and restarts the computer.
Does a blue screen mean I lost my files?
Not usually. Files saved on the drive remain. Unsaved work in open programs can be lost, so save often, and back up if the crashes continue.
How do I fix a blue screen error on Windows 10?
Note the stop code, remove new devices, undo the latest update or driver, run SFC and DISM, then test memory and disk. Use System Restore if the problem began recently.
What is stop code WHEA uncorrectable error?
It means the hardware reported a fault Windows could not correct. Check temperature, dust, overclocking settings, memory and power supply, and see a technician if it repeats.
Is a blue screen error caused by a virus?
Rarely. Drivers, memory and disk problems are far more common. A full scan with built-in Windows Security is still a sensible step.