System Idle process
is used for measuring how much idle time the CPU is having at any particular time (100% minus the sum of all tasks CPU usage). It accounts for processor time when the system is not processing other threads and will display how much CPU resources, as a percentage are 'idle' and available for use. One instance of this process operates per CPU, and runs to occupy the processor when other threads are not running. System Idle process also issues HLT commands which put unused parts of the CPU into a suspend mode, thereby cooling the processor. Normally this process should take up at least 90%+
of processor time on average (this is the value in the CPU column). In non-technical terms, this figure represents how much CPU time has not been requested by anything else on your system. See Why Is The System Idle Process Hogging All The Resources?
is a process in NT "kernel mode" that contains most of the system threads and handles various basic system functions. When Windows loads, the Windows kernel
starts and runs in kernel mode to set up paging and virtual memory. It then creates some system processes and allows them to run in "user mode" but restricts their access to critical areas of the operation system.
Every process started by Windows, except for the System process, runs in user mode. The User mode processes must request use of the kernel by means of a system call
in order to perform privileged operations on their behalf. Kernel mode has full access to system resources and controls scheduling, thread prioritization, interrupt handlers, memory management and the interaction with hardware. The system process cannot be terminated.
For more detailed information, please refer to: