The best solution we found was "hdparm -Y /dev/hdX" (and /dev/cdrom). It works on hard disks if not all CD-ROMs. The other noise is the power supply fan. Stock PCs offer no s/w fan control. Some PowerPC machines have it (although Ubuntu-PPC/Debian-PPC still has serious bugs). http://www.silentpcreview.com http://www.endpcnoise.com Mark