typedef struct _KPROCESS
{
     DISPATCHER_HEADER Header;
     LIST_ENTRY ProfileListHead;
     ULONG DirectoryTableBase;
     ULONG Unused0;
     KGDTENTRY LdtDescriptor;
     KIDTENTRY Int21Descriptor;
     WORD IopmOffset;
     UCHAR Iopl;
     UCHAR Unused;
     ULONG ActiveProcessors;
     ULONG KernelTime;
     ULONG UserTime;
     LIST_ENTRY ReadyListHead;
     SINGLE_LIST_ENTRY SwapListEntry;
     PVOID VdmTrapcHandler;
     LIST_ENTRY ThreadListHead;
     ULONG ProcessLock;
     ULONG Affinity;
     union
     {
          ULONG AutoAlignment: 1;
          ULONG DisableBoost: 1;
          ULONG DisableQuantum: 1;
          ULONG ReservedFlags: 29;
          LONG ProcessFlags;
     };
     CHAR BasePriority;
     CHAR QuantumReset;
     UCHAR State;
     UCHAR ThreadSeed;
     UCHAR PowerState;
     UCHAR IdealNode;
     UCHAR Visited;
     union
     {
          KEXECUTE_OPTIONS Flags;
          UCHAR ExecuteOptions;
     };
     ULONG StackCount;
     LIST_ENTRY ProcessListEntry;
     UINT64 CycleTime;
} KPROCESS, *PKPROCESS;

Windows Vista Kernel Structures