typedef struct 
{
     UCHAR PowerButtonPresent;
     UCHAR SleepButtonPresent;
     UCHAR LidPresent;
     UCHAR SystemS1;
     UCHAR SystemS2;
     UCHAR SystemS3;
     UCHAR SystemS4;
     UCHAR SystemS5;
     UCHAR HiberFilePresent;
     UCHAR FullWake;
     UCHAR VideoDimPresent;
     UCHAR ApmPresent;
     UCHAR UpsPresent;
     UCHAR ThermalControl;
     UCHAR ProcessorThrottle;
     UCHAR ProcessorMinThrottle;
     UCHAR ProcessorMaxThrottle;
     UCHAR FastSystemS4;
     UCHAR spare2[3];
     UCHAR DiskSpinDown;
     UCHAR spare3[8];
     UCHAR SystemBatteriesPresent;
     UCHAR BatteriesAreShortTerm;
     BATTERY_REPORTING_SCALE BatteryScale[3];
     SYSTEM_POWER_STATE AcOnLineWake;
     SYSTEM_POWER_STATE SoftLidWake;
     SYSTEM_POWER_STATE RtcWake;
     SYSTEM_POWER_STATE MinDeviceWakeState;
     SYSTEM_POWER_STATE DefaultLowLatencyWake;
} SYSTEM_POWER_CAPABILITIES, *PSYSTEM_POWER_CAPABILITIES;

Windows Vista Kernel Structures