Random blue screens

For the past few weeks Ive been getting many blue screens that pop up just whenever the hell they want to. The blue screen never has the same error message either. Recently its been "INTERRUPT_EXCEPTION_NOT_HANDLED", "IRQL_NOT_LESS_OR_EQUAL", and sometimes there isnt even an error message. Its just the "A problem has occurred..." message. How the hell do I troubleshoot something like this?

Check for:
 - cpu overheating
 - excessive dust in case
 - power supply problems
 - faulty hard drives or expansion cards