Вот определение, которое тебе может пригодится:
typedef enum _SYSTEM_INFORMATION_CLASS {
SystemBasicInformation,
SystemProcessorInformation,
SystemTimeOfDayInformation,
SystemPathInformation,
SystemProcessInformation,
SystemCallCountInformation,
SystemDeviceInformation,
SystemProcessorPerformanceInformation,
SystemFlagsInformation,
SystemCallTimeInformation,
SystemModuleInformation,
SystemLocksInformation,
SystemStackTraceInformation,
SystemPagedPoolInformation,
SystemNonPagedPoolInformation,
SystemHandleInformation,
SystemObjectInformation,
SystemPageFileInformation,
SystemVdmInstemulInformation,
SystemVdmBopInformation,
SystemFileCacheInformation,
SystemPoolTagInformation,
SystemInterruptInformation,
SystemDpcBehaviorInformation,
SystemFullMemoryInformation,
SystemLoadGdiDriverInformation,
SystemUnloadGdiDriverInformation,
SystemTimeAdjustmentInformation,
SystemSummaryMemoryInformation,
SystemNextEventIdInformation,
SystemEventIdsInformation,
SystemCrashDumpInformation,
SystemExceptionInformation,
SystemCrashDumpStateInformation,
SystemKernelDebuggerInformation,
SystemContextSwitchInformation,
SystemRegistryQuotaInformation,
SystemExtendServiceTableInformation,
SystemPrioritySeperation,
SystemPlugPlayBusInformation,
SystemDockInformation,
SystemPowerInformation,
SystemProcessorSpeedInformation,
SystemCurrentTimeZoneInformation,
SystemLookasideInformation
} SYSTEM_INFORMATION_CLASS;
Вот пример, как можно работать с функцией NtQuerySystemInformation
http://subscribe.ru/archive/comp.soft.prog.hitech/200311/01163215.html . Посмотри главу "Дампер процессов"