I have a 2 year old PII300 with a generic LX mobo and generic 235 watt powersupply. Whenever the hard drive cranks, the cpu cooler fan slows down, as soon as the HD stops cranking, the fan speeds up again. It is very noticiable. This just started a month or two ago. I know the fan is Ok, because I tested it in my main system. I am thinking it must be the Power supply or the Mobo. It is the only fan that slows down and it is also the only one plugged into the mobo. Anyone else have anything like this happen? What do you think could be causing it? Thanks for any input.