The Executive is the part of the Windows NT operating system that runs in Kernel mode. Kernel mode is a privileged processor mode in which a thread has access to system memory and to hardware. (In contrast, User mode is a nonprivileged processor mode in which a thread can only access system resources by calling system services.) The Windows NT Executive provides process structure, thread scheduling, interprocess communication, memory management, object management, object security, interrupt processing, I/O capabilities, and networking.
The Windows NT Kernel is the part of the Windows NT Executive that manages the processor. It performs thread scheduling and dispatching, interrupt and exception handling, and multiprocessor synchronization. It also provides primitive objects to the Windows NT Executive, which uses them to create User-mode objects.
There are three types of Windows NT Executive messages:
Many of these messages were created to cover everything else that could possibly happen, so you may never see them. For example, one of the STOP messages is "Unhandled Kernel exception." This message is only displayed after the Kernel exception dispatcher has exhausted its search of the Kernel call stack for exception-handling code. Similarly, a STATUS message announces the termination of a thread only after the Executive has searched the entire user call stack and the subsystem associated with the application for exception-handling code.
For help with hardware-malfunction messages, you should first contact a technician within your own organization to run hardware diagnostics on your computer. If you then need to find help outside your organization, contact the hardware vendor for your specific brand of computer, adapter, or peripheral device.
Most users will also need to ask for help with the STOP messages from a technical support person who has been trained to support Windows NT. Information on what you can do to help that trained technician use the Windows NT debugger application (WINDBG.EXE) appears in the "Windows NT Debugger" section at the end of this chapter.