0xA0x0000000A
IRQL_NOT_LESS_OR_EQUAL
Kernel-mode code, usually a driver, touched memory it was not allowed to use at that moment.
Causes and fixes →BSOD Error Code Lookup
Type the stop code from your Windows blue screen, either the name (CRITICAL_PROCESS_DIED) or the hex value (0xEF), to see what it means, what usually causes it and the safest order of fixes.
25 common stop codes
Driver errors
0xD10x000000D1
DRIVER_IRQL_NOT_LESS_OR_EQUAL
A driver tried to read or write pageable memory at a priority level where that is not allowed.
Causes and fixes →0x3B0x0000003B
SYSTEM_SERVICE_EXCEPTION
An error occurred while code moved from normal user mode into the privileged kernel.
Causes and fixes →0x7E0x0000007E
SYSTEM_THREAD_EXCEPTION_NOT_HANDLED
A Windows system thread raised an error that nothing handled, often tied to a named driver file.
Causes and fixes →0x1E0x0000001E
KMODE_EXCEPTION_NOT_HANDLED
A kernel-mode program, usually a driver, caused an exception that the error handler could not catch.
Causes and fixes →0x1330x00000133
DPC_WATCHDOG_VIOLATION
A driver task ran for too long and the watchdog timer stopped Windows. Storage drivers are common triggers.
Causes and fixes →0x9F0x0000009F
DRIVER_POWER_STATE_FAILURE
A driver did not respond correctly while the PC changed power state, such as sleeping, waking or shutting down.
Causes and fixes →Graphics and display errors
0x1160x00000116
VIDEO_TDR_FAILURE
The graphics driver stopped responding and did not recover in time after Windows tried to reset it.
Causes and fixes →0x1190x00000119
VIDEO_SCHEDULER_INTERNAL_ERROR
The Windows video scheduler, which hands work to the GPU, detected a fatal violation.
Causes and fixes →0x1130x00000113
VIDEO_DXGKRNL_FATAL_ERROR
The DirectX graphics kernel subsystem found a violation, usually related to the graphics driver or GPU.
Causes and fixes →0xEA0x000000EA
THREAD_STUCK_IN_DEVICE_DRIVER
A driver got stuck in a loop, often waiting for hardware that stopped responding. Graphics drivers are common.
Causes and fixes →Memory errors
0x500x00000050
PAGE_FAULT_IN_NONPAGED_AREA
Windows tried to use memory that should always be present in RAM and found it invalid or missing.
Causes and fixes →0x1A0x0000001A
MEMORY_MANAGEMENT
Windows hit a severe memory-management error, most often from faulty RAM or unstable memory settings.
Causes and fixes →0x190x00000019
BAD_POOL_HEADER
Windows found a damaged header in a block of memory it manages, the memory pool.
Causes and fixes →Storage and file system errors
0x240x00000024
NTFS_FILE_SYSTEM
The NTFS file system driver hit a problem it could not recover from.
Causes and fixes →0x7A0x0000007A
KERNEL_DATA_INPAGE_ERROR
Windows could not read a page of kernel data back from disk into memory.
Causes and fixes →0x1540x00000154
UNEXPECTED_STORE_EXCEPTION
The Windows store component, which handles memory compression and paging, caught an unexpected exception.
Causes and fixes →0x1C70x000001C7
STORE_DATA_STRUCTURE_CORRUPTION
The Windows store component detected corruption in its data structures.
Causes and fixes →Start-up and boot errors
0x7B0x0000007B
INACCESSIBLE_BOOT_DEVICE
Windows could not read the drive it boots from during start-up.
Causes and fixes →0xED0x000000ED
UNMOUNTABLE_BOOT_VOLUME
Windows found the boot drive but could not mount its file system.
Causes and fixes →Hardware and CPU errors
0x1240x00000124
WHEA_UNCORRECTABLE_ERROR
Windows received a fatal hardware error report from the processor, memory, a PCIe device or another component.
Causes and fixes →0x1010x00000101
CLOCK_WATCHDOG_TIMEOUT
A processor core did not respond to the system clock in time, often from unstable CPU settings.
Causes and fixes →0x7F0x0000007F
UNEXPECTED_KERNEL_MODE_TRAP
The processor raised a fault the kernel could not handle, often tied to memory, heat or overclocking.
Causes and fixes →System file and kernel errors
0xEF0x000000EF
CRITICAL_PROCESS_DIED
A process Windows cannot run without stopped or was damaged, so Windows halted to protect itself.
Causes and fixes →0x1390x00000139
KERNEL_SECURITY_CHECK_FAILURE
Windows detected corruption in a critical kernel data structure and stopped.
Causes and fixes →How to find your stop code
- Read the blue screen. Windows prints the stop code as text, for example CRITICAL_PROCESS_DIED, and sometimes a line starting with "What failed" that names a driver file.
- If the PC restarted too quickly, open Event Viewer, then Windows Logs, then System, and look for a BugCheck event with ID 1001. It records the code and its parameters.
- Open Reliability Monitor (search for it in Start) to see the date and time of each critical failure and whether it followed a change such as an update or driver install.
- Write down what you changed recently and whether the crash happens during gaming, idle, sleep or start-up. That context matters as much as the code.
Before you start fixing
A stop code names a type of failure, not always its cause. Back up important files first, make one change at a time, and avoid registry cleaners or "driver updater" programs. For the general approach, see Windows troubleshooting: the complete guide.
Frequently asked questions
How do I find my blue screen stop code?
Windows shows the stop code as text on the blue screen, for example CRITICAL_PROCESS_DIED. If the PC restarted before you could read it, open Event Viewer, then Windows Logs, then System, and look for a BugCheck event with ID 1001, which records the code. Reliability Monitor also lists critical events.
Does the hex code or the name matter more?
They identify the same bug check. The name is easier to search and read, while the hex value, for example 0x000000EF, appears in logs and dump files.
Can a blue screen be fixed without reinstalling Windows?
Often yes. Most stop codes come from drivers, memory, storage or system file problems that can be found and fixed in order. Reinstalling Windows is a last resort, and it does not fix failing hardware.
Is the stop code enough to diagnose the problem?
Not on its own. A code names the type of failure, and several causes can lead to the same code. Use it to choose the first checks, then look at what changed recently and whether the crash repeats under the same conditions.