A blue screen that appears when the Microsoft Windows NT or Windows 2000 operating system experiences a fatal problem and terminates itself.
The most important part of a Stop screen is the bugcheck information in the first few lines, which gives a Stop code and parameters that can help identify the source of the problem to Microsoft support technicians.
A Stop screen includes the following information:
The following table shows some common bugcheck codes and how to interpret them.
| Code | Description |
| 0x9 | IRQL_NOT_GREATER_OR_EQUAL: An attempt was made to touch pageable memory at a process interrupt request level (IRQL) that was too high. This usually indicates that a driver is using improper addresses. A stack trace is usually helpful in debugging the problem. |
| 0xA | IRQL_NOT_LESS_OR_EQUAL: Usually indicates a bad or corrupt pointer. |
| 0x1E | KMODE_EXCEPTION_NOT_HANDLED: An exception (error) occurred with a driver or function. This is one of the most common bugcheck codes; you can often use the exception address to identify the driver or function involved. |
| 0x20 | KERNEL_APC_PENDING_DURING_EXIT: This usually indicates a problem with a third-party file system driver, such as a third-party redirector. Check with the manufacturer for an updated redirector. |
| 0x2E | DATA_BUS_ERROR: This usually indicates a parity error in system memory. Try installing new RAM. It can also be caused by a driver accessing an address that does not exist; if swapping memory does not solve the problem, try swapping other hardware cards or install updated drivers for them. |
| 0x3E | MULTIPROCESSOR_CONFIGURATION_NOT_SUPPORTED: This indicates mismatched CPUs in a symmetric multiprocessing (SMP) system. |
| 0x4C | FATAL_UNHANDLED_HARD_ERROR: An error prevented the Windows NT operating system from booting properly. Common causes are missing or corrupt registry hives, corrupt system dynamic-link library (DLL), corrupt device driver, or an I/O problem with the disk subsystem. |
| 0x51 | REGISTRY_ERROR: This could mean corruption in the registry or an I/O problem with the disk subsystem that prevents it from properly reading registry information. This error might also occur on a domain controller in which no more allocated space is available for storing the registry files. |
| 0x69 | IO1_INITIALIZATION_FAILED: This indicates a failure in initializing the disk subsystem and usually means that you made an incorrect configuration decision during setup or have reconfigured the disk system incorrectly. |
| 0x73 | CONFIG_LIST_FAILED: This indicates corruption in the SAM, SOFTWARE, or SECURITY hive. |
| 0x74 | BAD_SYSTEM_CONFIG_INFO: This might indicate a corrupt SYSTEM hive in the registry, or it might mean that some critical registry keys in the hive are not present. Try LastKnownGood; if that fails, try the emergency repair disk (ERD). |
| 0x75 | CANNOT_WRITE_CONFIGURATION: This usually indicates that there are 0 bytes of free space on the system drive, so the SYSTEM hive of the registry cannot grow in size. |
| 0x77 | KERNEL_STACK_INPAGE_ERROR: This is usually caused by a bad block in the paging file or a disk controller error. If the paging file is on a Small Computer System Interface (SCSI) drive, check the cabling and termination. |
| 0x7B | INACCESSIBLE_BOOT_DEVICE: If this occurs right after setup, it might mean that your disk controller is not supported by Windows NT. You might have to check the Windows Driver Library for a new device driver and do a custom installation. This error can also occur when you repartition the disk that contains the system partition. The solution is to edit the ARC paths in the boot.ini file. Another reason for this error is a Master Boot Record (MBR) or boot sector virus. |
| 0x8B | MBR_CHECKSUM_MISMATCH: This usually indicates the presence of a Master Boot Record virus. |
| 0x98 | END_OF_NT_EVALUATION_PERIOD: Your evaluation copy of Windows NT has expired. |
Sometimes you can compare the addresses of the parameters in the top portion of the Stop screen with the addresses of drivers in the stack dump at the bottom and identify which driver might have caused the crash, but this will not always work. For more information on bugcheck codes and how to interpret them, check Microsoft TechNet.