typedef enum _KOBJECTS
{
         EventNotificationObject = 0,
         EventSynchronizationObject = 1,
         MutantObject = 2,
         ProcessObject = 3,
         QueueObject = 4,
         SemaphoreObject = 5,
         ThreadObject = 6,
         GateObject = 7,
         TimerNotificationObject = 8,
         TimerSynchronizationObject = 9,
         Spare2Object = 10,
         Spare3Object = 11,
         Spare4Object = 12,
         Spare5Object = 13,
         Spare6Object = 14,
         Spare7Object = 15,
         Spare8Object = 16,
         Spare9Object = 17,
         ApcObject = 18,
         DpcObject = 19,
         DeviceQueueObject = 20,
         EventPairObject = 21,
         InterruptObject = 22,
         ProfileObject = 23,
         ThreadedDpcObject = 24,
         MaximumKernelObject = 25
} KOBJECTS;

Windows Vista Kernel Structures