8a420f71_BSOD_Index__Parameter_4
[Parameter 1] 0x500 (Windows XP and Windows Server 2003 only) [Parameter 2] Reserved [Parameter 3] The target device's device object, if available [Cause] The device object completed the IRP for the system power state request, but it failed to call PoStartNextPowerIrp. [Parameter 4] 
Device object
BSOD Index
Parameter 4