typedef enum _WOW64_SHARED_INFORMATION
{
         SharedNtdll32LdrInitializeThunk = 0,
         SharedNtdll32KiUserExceptionDispatcher = 1,
         SharedNtdll32KiUserApcDispatcher = 2,
         SharedNtdll32KiUserCallbackDispatcher = 3,
         SharedNtdll32LdrHotPatchRoutine = 4,
         SharedNtdll32ExpInterlockedPopEntrySListFault = 5,
         SharedNtdll32ExpInterlockedPopEntrySListResume = 6,
         SharedNtdll32ExpInterlockedPopEntrySListEnd = 7,
         SharedNtdll32RtlUserThreadStart = 8,
         SharedNtdll32pQueryProcessDebugInformationRemote = 9,
         SharedNtdll32EtwpNotificationThread = 10,
         SharedNtdll32BaseAddress = 11,
         Wow64SharedPageEntriesCount = 12
} WOW64_SHARED_INFORMATION;

Windows Vista Kernel Structures