I have a 600 MHz iMac G3 (one of the last ones available before the G4 iMac came out) and it is very loud when it is on. I'm not sure if it's the hard drive or the fan (probably hard drive). Does anybody have any tips/suggestions as to how I can make it quiet? When my titanium G4 powerbook is on, I can hear a thing. When my iMac is on, I need to take Advil because of all the headaches it gives me.