VH, the reason that your computer is running more quietly on the Ubuntu Demo is that...well, your Hard drive sucks. You see, on the Demo, the hard drive is turned on, with the CD drive acting as a hard drive. Thus, I would suggest a nicer hard drive, if you care about sound. I would suggest a 500 Gig Quiet Western Digital Caviar SE16 Hard Drive. Depending on your current computer, this might be an upgrade. I am using this Hard drive and there is never hear any sound coming from it. Also, if your computer isn't water cooled, try getting the biggest fans possible. The bigger, the slower they have to go, resulting in noise reduction.