ntoskrnl.exe (short for Windows NT operating system kernel executable) contains the kernel and executive layers of the Microsoft Windows NT kernel space, and is responsible for various system services such as hardware abstraction, process and memory management, thus making it a fundamental part of the system. It contains the cache manager, the executive, the kernel, the security reference monitor, the memory manager, scheduler (Dispatcher), and the text and some coding for the Stop Error Screen (Blue Screen of Death).