My wife's pc has been acting stragely recently. She has just updated her processor/motherboard. This seemed to cause the power supply to go 'south' (pc would not switch on or anything) so a new power supply was installed (430w) that we were led to believe would solve the problem. The new pc has two cooling fans and an extra fan was also fitted below the power supply to help air flow. All seemed ok until my wife was burning a dvd this morning and the pc just 'shut off'. On investiagtion I found that it still was powered up but there was nothing on screen, I rebooted and as far as I can tell all is well. It has just done the same thing again, but what I do observe is that on the o/s of the case where the power supply is there does seem to be a 'reasonable' amount of heat coming through the case? The pc is enclosed but not at the back and there is a door on the front. She is running XP pro with a P4 3.4ghz & a Biostar P4M80-M4 motherboard (has a 478/FSB 800mhz,AGP 8X,DDR 400), anyone got any ideas as to whats going on?