The kernel is responsible for scheduling all system actions, handling system interrupts and handles processor exceptions. On a multiprocessor system, a copy of the kernel actually runs on each processor. Because the kernel is involved in almost every action taken on an NT system, critical portions of the kernel are written in assembly language. Object Manager - The Object Manager piece of the NT Executive is used to create, modify, and delete objects used by all the systems that make up the NT Executive. Objects are abstract data types that are used to represent operating system resources.
Objects can be concrete, such as device port, or they can be more abstract, such as a thread.
When an object is created, it is given a name by which other programs can access the object. Process Manager - The Process Manager is responsible for creating, removing, and modifying the states of all processes and threads. It also provides information on the status of processes and threads to the rest of the system. When an application is started, it is created as a process, which requires a call to the Process Manager. Because every process must have at least one thread, the Process Manager is invoked again to create a thread.