Blue screen errors
Find your stop code, then follow the guide written for it.
A blue screen (stop error or bug check) means Windows found a problem it could not safely recover from, so it stopped and restarted to protect your data. The stop code names the condition Windows detected. It narrows the cause down, but the same code can come from a driver, the memory or another part of the hardware.
Start by finding the exact stop code and any file named next to "What failed". Then open the matching guide below. Each guide is checked against Microsoft's bug check documentation and lists its steps in the order that usually finds the cause fastest.
How to find the stop code
- On the blue screen, note the text after "Stop code" and the file after "What failed", if shown. Taking a photo with your phone is the easiest way.
- If the PC restarts too quickly, open Event Viewer (Win + R, eventvwr.msc) > Windows Logs > System and look for event ID 1001 from BugCheck. It contains the code, for example 0x00000133.
- Reliability Monitor (search "View reliability history") shows each crash by date, which helps you link it to an update or a new driver.
- Windows saves crash dumps in C:\Windows\Minidump. A technician or the PC maker's support can open them to find the driver responsible.
Driver problems
These stop codes usually mean a driver did something Windows does not allow, did not respond in time or failed during sleep. Updating, rolling back or removing the driver is the main fix.
SYSTEM_SERVICE_EXCEPTION
Windows stopped because code running in the system kernel hit an exception, usually a bad memory address, while handling a request from a normal program. In practice the faulty code almost always belongs to a driver:…
DriversSYSTEM_THREAD_EXCEPTION_NOT_HANDLED
Windows stopped because a system thread, code that runs inside Windows itself, hit an error that nothing caught, most often an invalid memory access. In almost every case the thread belongs to a driver, and the blue…
Windows & BSODKMODE_EXCEPTION_NOT_HANDLED
Windows stopped because a program running in kernel mode, almost always a driver or system service, caused an error that nothing caught. Microsoft lists three main sources: a faulty device driver or system service,…
Windows & BSOD0x0000000A
Windows stopped because a driver or Windows itself accessed memory at an invalid address while running at a raised priority level (IRQL). The cause is typically a bad memory pointer in a driver.
DriversDRIVER_IRQL_NOT_LESS_OR_EQUAL
Windows stopped because a kernel-mode driver tried to access memory at an invalid address while running at a raised priority level. Microsoft says this bug check is usually caused by drivers that used improper memory…
Windows & BSODDPC_WATCHDOG_VIOLATION
Windows stopped because a driver held the processor for too long. Drivers handle hardware events in short, high-priority routines (deferred procedure calls, DPCs), and a watchdog in Windows triggers this stop code…
DriversDRIVER-POWER-STATE-FAILURE
Windows stopped because a device driver did not finish a power change, such as sleep, wake-up or shutdown, in time. This also covers devices that Windows turns off to save power.
GraphicsVIDEO_TDR_FAILURE
Windows tried to recover an unresponsive graphics driver, but the recovery failed.
Windows & BSOD0x000000FC
Windows stopped because a driver tried to run code from memory that is marked as data only (non-executable). The processor's No-Execute protection blocks this, because running code from data memory is how both buggy…
Windows & BSOD0x000000C2
Windows stopped because a driver made an invalid request for kernel memory, such as freeing the same memory twice. Requesting memory at a priority level where that is not allowed causes it too.
Memory and system data
Windows found memory or internal data that was damaged. Faulty or overclocked RAM is a common cause, but drivers and damaged system files can produce the same codes.
MEMORY_MANAGEMENT
Windows stopped because it found a severe error in how memory is managed, such as damaged page tables or memory records that no longer match. Microsoft describes several of its specific error types as probably…
Windows & BSOD0x00000050
Windows stopped because it tried to use system memory at an address that is not valid, usually a wrong address or memory that was already freed. Microsoft lists three main sources: a faulty driver or system service,…
MemoryBAD_POOL_HEADER
Windows stopped because it found damaged bookkeeping data (a pool header) in the kernel's memory pool, the shared memory drivers use. Microsoft notes that the pool was already corrupted when the crash happened, so…
Windows & BSODFAULTY_HARDWARE_CORRUPTED_PAGE
Windows stopped because its memory manager found memory corruption caused by hardware or a driver writing to memory directly. Microsoft says such corruption can only come from access by physical address, not through…
Windows & BSODKERNEL_SECURITY_CHECK_FAILURE
Windows stopped because the kernel found that one of its critical internal data structures had been corrupted. Windows checks these structures on purpose and stops rather than continue with damaged data.
DriversCRITICAL_STRUCTURE_CORRUPTION
Windows stopped because it detected that critical kernel code or data had been changed. 64-bit Windows does not allow its kernel to be modified except by Microsoft's own hot patches, so when something changes it,…
MemoryMEMTEST-ERR-8
A memory test such as MemTest86 or Windows Memory Diagnostic reported errors: data written to RAM did not read back correctly. Errors like this can cause crashes, blue screens and corrupted files.
Hardware errors reported by the processor
The processor reported a hardware error, stopped responding or hit an error the kernel could not handle. Overclocks, memory, temperatures, power and the BIOS come first here, before drivers.
WHEA_UNCORRECTABLE_ERROR
Windows stopped because a piece of hardware reported an error that could not be corrected. WHEA (Windows Hardware Error Architecture) is the part of Windows that collects these reports, so the stop code says who…
ProcessorMACHINE_CHECK_EXCEPTION
The processor detected a hardware error it could not correct and stopped Windows to prevent data corruption. On current Windows versions the same event usually appears as WHEA_UNCORRECTABLE_ERROR (0x124); the older…
ProcessorCLOCK_WATCHDOG_TIMEOUT
Windows stopped because one of the processor's cores did not respond to a regular clock signal in time. Microsoft explains that the core is usually unresponsive or deadlocked.
Windows & BSODUNEXPECTED_KERNEL_MODE_TRAP
Windows stopped because the processor raised an error (a trap) inside the Windows kernel that the kernel could not handle. A common example is a double fault: an error that happens while the processor is already…
Drive and file system errors
Windows could not read data it needed from the drive, or the file system on it is damaged. Back up your files first, then check the drive with chkdsk and its maker's tool.
KERNEL_DATA_INPAGE_ERROR
Windows stopped because it could not read a page of its own kernel data back from the paging file on the drive into memory. Microsoft's list of causes points mostly at storage: bad sectors on the drive, a loose or…
StorageNTFS_FILE_SYSTEM
Windows stopped because of a problem in ntfs.sys, the driver that reads and writes NTFS drives. The blue screen often names ntfs.sys after "What failed".
Startup and system processes
Windows lost access to its drive while starting, or a process it cannot run without stopped. These often need the Windows recovery environment.
INACCESSIBLE_BOOT_DEVICE
Windows lost access to the drive it starts from while it was booting, so it cannot continue. Microsoft lists the typical triggers: a changed storage controller mode in the BIOS (for example AHCI or RAID), a new disk…
Windows & BSOD0x000000EF
Windows stopped because a system process it cannot run without ended unexpectedly. These processes manage things like sign-in, sessions and system services, so Windows treats their loss as fatal and restarts.
Windows & BSOD0xC000021A
Windows stops with code 0xC000021A, often during startup or right after an update. Microsoft names this bug check WINLOGON_FATAL_ERROR: a user-mode subsystem that Windows cannot run without, such as Winlogon or the…
The PC restarts without showing a blue screen
Windows only logs that the last shutdown was not clean. The event details tell you whether it was a hidden blue screen, the power button or a power or hardware problem.
First steps for any blue screen
If your stop code is not listed yet, these checks from Microsoft's general stop error troubleshooting fix many cases. Do them in order and test after each one.
- Undo the most recent change: a new driver, Windows update, program or piece of hardware.
- Install current drivers for graphics, chipset, network and storage from the device or PC maker, and run Windows Update.
- Turn off overclocks, including XMP or EXPO memory profiles, and check that the PC is not overheating.
- Run Windows Memory Diagnostic (mdsched.exe) to test the RAM.
- In Terminal (Admin), run DISM /Online /Cleanup-Image /RestoreHealth and then sfc /scannow to repair system files.
- Run chkdsk C: /scan to check the system drive for file system errors.
- If Windows keeps crashing, start it in Safe Mode, which loads only basic drivers, and do the steps from there.
Sources
- Microsoft Learn: Stop code error or bug check troubleshooting
- Microsoft Learn: Bug check code reference
Written and reviewed by Matyáš Rada.