typedef struct _POP_POWER_ACTION
{
     UCHAR Updates;
     UCHAR State;
     UCHAR Shutdown;
     POWER_ACTION Action;
     SYSTEM_POWER_STATE LightestState;
     ULONG Flags;
     LONG Status;
     POP_POLICY_DEVICE_TYPE DeviceType;
     ULONG DeviceTypeFlags;
     UCHAR IrpMinor;
     UCHAR Waking;
     SYSTEM_POWER_STATE SystemState;
     SYSTEM_POWER_STATE NextSystemState;
     SYSTEM_POWER_STATE EffectiveSystemState;
     SYSTEM_POWER_STATE CurrentSystemState;
     PPOP_SHUTDOWN_BUG_CHECK ShutdownBugCode;
     PPOP_DEVICE_SYS_STATE DevState;
     PPOP_DISPLAY_RESUME_CONTEXT DisplayResumeContext;
     PPOP_HIBER_CONTEXT HiberContext;
     UINT64 WakeTime;
     UINT64 SleepTime;
     SYSTEM_POWER_STATE_CONTEXT SystemContext;
     SYSTEM_POWER_CAPABILITIES FilteredCapabilities;
} POP_POWER_ACTION, *PPOP_POWER_ACTION;

Windows Vista Kernel Structures