CrashDecoder: Plain-English answers for Windows stop codes and hardware errors
Windows tells you something broke using a hexadecimal code and a string of capital letters. These pages translate that into what actually failed, what to check first, and how to tell a driver problem from hardware that is on its way out.
Do not have your stop code yet?
Current Windows reboots from the crash screen in about two seconds, which is not long enough to read anything. Here is how to recover the code afterwards - and how to make the screen wait for you next time.
Start with your error
- 0x0000000AIRQL_NOT_LESS_OR_EQUALA driver accessed memory at an interrupt level too high to survive the fault. Nearly always a driver.
- 0x00000019BAD_POOL_HEADERA pool header was corrupt. The blamed driver is usually the one next door.
- 0x0000001AMEMORY_MANAGEMENTWindows' memory bookkeeping is corrupt. The first parameter tells you which kind, and that changes everything.
- 0x0000001EKMODE_EXCEPTION_NOT_HANDLEDKernel code faulted with no handler. Parameter 1 names the exception type.
- 0x00000024NTFS_FILE_SYSTEMA fault inside the NTFS driver. Almost always the disk under it, not the driver.
- 0x0000003BSYSTEM_SERVICE_EXCEPTIONA kernel fault during a system call. Usually a driver, sometimes memory, occasionally a dying board.
- 0x00000050PAGE_FAULT_IN_NONPAGED_AREAMemory that could never be paged out was missing anyway. Points harder at RAM than most codes.
- 0x0000007AKERNEL_DATA_INPAGE_ERRORWindows couldn't read data back from disk. Parameter 2 usually names the exact cause.
- 0x0000007BINACCESSIBLE_BOOT_DEVICEWindows couldn't reach its own boot drive. Check UEFI storage mode before anything else.
- 0x0000007ESYSTEM_THREAD_EXCEPTION_NOT_HANDLEDA system thread faulted with no handler. Usually prints the guilty driver right on the screen.
- 0x0000009CMACHINE_CHECK_EXCEPTIONA fatal processor machine check. On modern Windows, seeing this rather than 0x124 is informative.
- 0x0000009FDRIVER_POWER_STATE_FAILUREA driver stalled during sleep, wake or shutdown. Timing tells you almost everything.
- 0x000000C2BAD_POOL_CALLERA driver misused kernel memory allocation. Verifier with pool options finds it reliably.
- 0x000000D1DRIVER_IRQL_NOT_LESS_OR_EQUALA driver touched bad memory at raised IRQL. Usually names itself on the blue screen.
- 0x000000EATHREAD_STUCK_IN_DEVICE_DRIVERA driver thread is spinning forever waiting for hardware. Nearly always the graphics card.
- 0x000000EFCRITICAL_PROCESS_DIEDA process Windows can't live without exited. Often a boot loop, so the fixes run from recovery.
- 0x000000F4CRITICAL_OBJECT_TERMINATIONA process or thread Windows needs has exited. Parameter 3 names which one.
- 0x00000101CLOCK_WATCHDOG_TIMEOUTOne CPU core stopped answering. Overclocks and undervolts cause most of these.
- 0x00000109CRITICAL_STRUCTURE_CORRUPTIONKernel Patch Protection caught something modifying the kernel. Or memory corrupted it.
- 0x00000116VIDEO_TDR_FAILUREThe GPU stopped answering and Windows gave up waiting. Driver, heat, power, or a dying card.
- 0x00000124WHEA_UNCORRECTABLE_ERRORThe hardware reported a fatal error directly. The most hardware-specific stop code there is.
- 0x0000012BFAULTY_HARDWARE_CORRUPTED_PAGEWindows caught a bit that changed on its own. One of the clearest hardware signals there is.
- 0x00000133DPC_WATCHDOG_VIOLATIONA driver hogged the CPU past a hard deadline. Storage firmware and SATA drivers cause most of them.
- 0x00000139KERNEL_SECURITY_CHECK_FAILUREA kernel integrity check caught corruption and halted deliberately. Parameter 1 says which kind.
- 0x0000013AKERNEL_MODE_HEAP_CORRUPTIONThe kernel heap manager caught corruption. Parameter 1 names which kind, precisely.
- 0x00000154UNEXPECTED_STORE_EXCEPTIONMemory compression hit an error it couldn't handle. Check the drive before the RAM.
- 0xC000021AWINLOGON_FATAL_ERRORWinlogon or csrss has failed and security can no longer be guaranteed. Usually a hard lockout.
- disk / NtfsStorage and filesystem error events - which ones mean a dying driveA dozen storage events, mostly harmless. Four justify replacing a drive. Here's which.
- Display 4101Display driver stopped responding and has successfully recoveredThe GPU hung and recovered. Count incidents, not records - NVIDIA logs four per event.
- Kernel-Power 41The system has rebooted without cleanly shutting down firstThe machine went down hard. One field tells you whether it was a blue screen or a power loss.
- WHEA-Logger 17A corrected hardware error has occurredHardware reported an error and recovered. One is noise. A burst of them is a warning.
- WHEA-Logger 18A fatal hardware error has occurred - Processor CoreThe CPU hit an error it could not correct. Often logged with no blue screen at all.
- WHEA-Logger 19A corrected hardware error has occurred - Processor CoreThe CPU caught an error and corrected it. Whether to care depends on the rate.
- WHEA-Logger 47A corrected hardware error has occurred - MemoryA memory error was corrected. The message hides the DIMM location; the XML doesn't.
Diagnostic guides
- GuideUsing Driver Verifier SafelyThe tool that names a bad driver. Plus the boot-fail flag that makes it safe to use.
- GuideFinding Your Crash History in WindowsBuild a timeline of every crash the machine recorded. The pattern beats any single dump.
- GuideHow to Find Your Windows Stop CodeThe screen vanishes in two seconds now. Here are four ways to get the code back.
- GuideHow to Read a Windows Crash Dump FileInstall WinDbg, open the dump, run one command. Fifteen minutes, and it usually names the driver.
- GuideHow to Test Your RAM ProperlyTwo different questions: is a module defective, or are your settings unstable? Different tools.
- GuideLiveKernelEvent: Hardware Errors Without a Blue ScreenReliability Monitor's 'Hardware error' entries. No crash, real dump file, poorly documented codes.
How to use this site
Search the exact code Windows gave you, including the 0x prefix. If you only have an Event Viewer entry rather than a blue screen, look under hardware errors instead: those are the events that get logged while the machine is still running.
One honest caveat
A single stop code rarely identifies a single faulty part. What it gives you is a starting direction. Every page here separates what the code proves from what it merely suggests, because guessing wrong costs money.