Interrupts Time

Exists in Windows NT/2000/XP only. It is a placeholder for hardware interrupts statistics. It also has pseudo threads for each CPU in system. You can see how much time CPUs "live" in interrupts in "CPU" and "CPU %" columns and how many interrupts per second are processed by each CPU in "Sw/s" field (see also description of process pane). You may be surprised how much time your system spends for processing hardware interrupts during active work with IDE disk in non UDMA mode! Note that executing of threads is blocked during processing of interrupts.

DPC Time

Exists in Windows NT/2000/XP only. It is a placeholder for deferred procedure calls (DPC) statistics. It also has pseudo threads for each CPU in System. You can see how much time CPUs "live" in DPC in "CPU" and "CPU %" columns and how many DPCs per second are processed by each CPU in "Sw/s" field. DPC is a next step in processing after interrupt. It has lower "hardware" priority than interrupt state and not blocks interrupts processing. Note that DPC blocks execution of threads on the same CPU.

Idle

All idle CPU time (percent of CPU time not used by any process) is collected here. In Windows NT/2000/XP Idle process contains one thread for each CPU in the system. So if you have two CPUs you will have two ‘Idle’ threads.

VMs

DOS virtual machines, exist in Windows 9x (95/98/ME) only. TaskInfo shows title of DOS VM window as process name. When you start a console application you have three components running: the console application itself, DOS virtual machine and ‘winoldap.exe’ that really performs console input/output and some other operations. CPU usage of this is not visible to the Windows 95 monitor utility.

NTKern

Exists in Windows9x (95/98/ME) only. NT WDM drivers support VxD. This pseudo process contains threads that are not owned by any Windows process, for example, NT kernel emulator worker threads. CPU usage of these threads is not visible to the Windows 9x "Wintop.exe" utility from ‘Kernel Toys’ package or to the Windows 9x monitor utility. For example, if you use a soundcard with WDM driver (kernel WDM audio mixer) and software MIDI synthesizer, you can see its CPU usage in NTKern pseudo process.

VxD Unknown

Exists in Windows 9x (95/98/ME) only. It is a holder for all threads created by some badly behaving VxDs. So that it is not possible to determine owner of this thread. For example, one of such VxD is a part of "GoBack" application from "Wild Files/Adaptec".