I have a Acer7200D Pentium 4 1.8. Have gone from onboard sound to Sblive 5.1, to a 128 mg Ati 9600SE video card, and ram from 256 to 768 (do math 528 + 256) but I never upgraded power supply, could this be a cause of crashes. Tried to find what I have for power supply think it is 250 watts.