typedef struct _KTHREAD
{
     DISPATCHER_HEADER Header;
     UINT64 CycleTime;
     ULONG HighCycleTime;
     UINT64 QuantumTarget;
     PVOID InitialStack;
     PVOID StackLimit;
     PVOID KernelStack;
     ULONG ThreadLock;
     union
     {
          KAPC_STATE ApcState;
          UCHAR ApcStateFill[23];
     };
     CHAR Priority;
     WORD NextProcessor;
     WORD DeferredProcessor;
     ULONG ApcQueueLock;
     ULONG ContextSwitches;
     UCHAR State;
     UCHAR NpxState;
     UCHAR WaitIrql;
     CHAR WaitMode;
     LONG WaitStatus;
     union
     {
          PKWAIT_BLOCK WaitBlockList;
          PKGATE GateObject;
     };
     union
     {
          ULONG KernelStackResident: 1;
          ULONG ReadyTransition: 1;
          ULONG ProcessReadyQueue: 1;
          ULONG WaitNext: 1;
          ULONG SystemAffinityActive: 1;
          ULONG Alertable: 1;
          ULONG GdiFlushActive: 1;
          ULONG Reserved: 25;
          LONG MiscFlags;
     };
     UCHAR WaitReason;
     UCHAR SwapBusy;
     UCHAR Alerted[2];
     union
     {
          LIST_ENTRY WaitListEntry;
          SINGLE_LIST_ENTRY SwapListEntry;
     };
     PKQUEUE Queue;
     ULONG WaitTime;
     union
     {
          struct
          {
               SHORT KernelApcDisable;
               SHORT SpecialApcDisable;
          };
          ULONG CombinedApcDisable;
     };
     PVOID Teb;
     union
     {
          KTIMER Timer;
          UCHAR TimerFill[40];
     };
     union
     {
          ULONG AutoAlignment: 1;
          ULONG DisableBoost: 1;
          ULONG EtwStackTraceApc1Inserted: 1;
          ULONG EtwStackTraceApc2Inserted: 1;
          ULONG CycleChargePending: 1;
          ULONG CalloutActive: 1;
          ULONG ApcQueueable: 1;
          ULONG EnableStackSwap: 1;
          ULONG GuiThread: 1;
          ULONG ReservedFlags: 23;
          LONG ThreadFlags;
     };
     union
     {
          KWAIT_BLOCK WaitBlock[4];
          struct
          {
               UCHAR WaitBlockFill0[23];
               UCHAR IdealProcessor;
          };
          struct
          {
               UCHAR WaitBlockFill1[47];
               CHAR PreviousMode;
          };
          struct
          {
               UCHAR WaitBlockFill2[71];
               UCHAR ResourceIndex;
          };
          UCHAR WaitBlockFill3[95];
     };
     UCHAR LargeStack;
     LIST_ENTRY QueueListEntry;
     PKTRAP_FRAME TrapFrame;
     PVOID FirstArgument;
     union
     {
          PVOID CallbackStack;
          ULONG CallbackDepth;
     };
     PVOID ServiceTable;
     UCHAR ApcStateIndex;
     CHAR BasePriority;
     CHAR PriorityDecrement;
     UCHAR Preempted;
     UCHAR AdjustReason;
     CHAR AdjustIncrement;
     UCHAR Spare01;
     CHAR Saturation;
     ULONG SystemCallNumber;
     ULONG Spare02;
     ULONG UserAffinity;
     PKPROCESS Process;
     ULONG Affinity;
     PKAPC_STATE ApcStatePointer[2];
     union
     {
          KAPC_STATE SavedApcState;
          UCHAR SavedApcStateFill[23];
     };
     CHAR FreezeCount;
     CHAR SuspendCount;
     UCHAR UserIdealProcessor;
     UCHAR Spare03;
     UCHAR Iopl;
     PVOID Win32Thread;
     PVOID StackBase;
     union
     {
          KAPC SuspendApc;
          struct
          {
               UCHAR SuspendApcFill0[1];
               CHAR Spare04;
          };
          struct
          {
               UCHAR SuspendApcFill1[3];
               UCHAR QuantumReset;
          };
          struct
          {
               UCHAR SuspendApcFill2[4];
               ULONG KernelTime;
          };
          struct
          {
               UCHAR SuspendApcFill3[36];
               PKPRCB WaitPrcb;
          };
          struct
          {
               UCHAR SuspendApcFill4[40];
               PVOID LegoData;
          };
          UCHAR SuspendApcFill5[47];
     };
     UCHAR PowerState;
     ULONG UserTime;
     union
     {
          KSEMAPHORE SuspendSemaphore;
          UCHAR SuspendSemaphorefill[20];
     };
     ULONG SListFaultCount;
     LIST_ENTRY ThreadListEntry;
     LIST_ENTRY MutantListHead;
     PVOID SListFaultAddress;
     PVOID MdlForLockedTeb;
} KTHREAD, *PKTHREAD;

Windows Vista Kernel Structures