bsod - Windows 7 x64 blue screen of death

I've been running Windows 7 Ultimate 64-bit on my HP EliteBook 8530w for a few months now, and during that time, it has blue-screen-of-deathed three times.

This time, I was able to snap a pic with my cellphone before it automatically rebooted:

Any idea what might be causing this?

EDIT:

I ran BlueScreenView, which showed 6 crahes:

Bug Check String            Caused By Driver
----------------            ----------------
IRQL_NOT_LESS_OR_EQUAL      hal.dll
DRIVER_POWER_STATE_FAILURE  ntsokrnl.exe
DRIVER_POWER_STATE_FAILURE  ntsokrnl.exe
BAD_POOL_CALLER             NETw5s64.sys
SYSTEM_SERVICE_EXCEPTION    ntsokrnl.exe
DRIVER_POWER_STATE_FAILURE  ntsokrnl.exe