I have had a couple of Compaq desktops and they are really quiet...or so my other half says. I have a hearing impairment so it really doesnt make a difference if a jet engine was inside the box! I can always turn off my hearing aid and all is silent.
I recently purchased a HP Business Desktop and the only loud noise that I could hear was during startup.
Recently the Forum editor purchased a compaq desktop pc from PC World and he commented that the "machine was quietly purring away"