Although most of a computer's noise is the hard drive. I have found every PC to be loud in all sorts of ways. And the worst feeling is you can't get rid of the noise without spending some serious money. In college I had no spare change at all and my best solution at the time was to compute in a loud environment and hope it cancels out all the hard drive and fan noises. It means time spent with the laptop in the cafeteria. Or leaving the dorm room open. As a last resort you can cancel out the noise with an Enya or a Tori Amos. There are times when you can't have all that much man-made noise. For example when your friends or love-ones are living with you and they can't handle the music. In that case you gotta resort to washable reusable ear-plugs you can get at any reputable drug store. Or at least make peace with a pleasant white noise like the soft sound of an electronic fan or the sound of leaves rustling in the wind.
If you think you can spend a little money consider what I am doing lately. My company has assigned me a dinky little laptop. It's very underwelming--a lowly Intel-compatible Processor called the K6-2 running at 333MHz, or in almost non-tech speak--a computer considered somewhat powerful in 1999--a computer 4 to 8 times slower than your average office PC in 2002. Anyway with a computer like this running Windows 98 it will basically shut off the fans and hard drives if all you ever do is read electronic text using Adobe Acrobat or surf non-multimedia sites with a web-browser. So I thought about the possibility of running Microsoft Terminal Services Client on my laptop. In the right conditions this laptop will never spin up its hard disk or fan. And if so it is rare.
This is lucky for me because in another room is a very very very loud home PC. It's a typical noise offender. It's got a fan over the main processor; one over the video card; and the ridiculously loud hard drive. On a good day it's almost quieter than most portable vacuum cleaners. I don't hate using it, especially when all I do is play MP3 or watching streaming newscasts. But I simply can't program or read anything on this PC.
So I enabled a feature call Microsoft Terminal Services on the Windows 2000 Server-based home PC and installed the corresponding client on my laptop. Instant bliss. I am typing this node right now with nothing but a very long ethernet cable and a door between me and that loud computer and it's all very nice.
You need to resort to work arounds like this sometimes because 1) You can't afford to pay hundreds of dollars to modify the fans and hand-pick quiet storage devices. 2) You know putting that loud PC in a thick metal sound barrier is a big no-no (it will simply overheat and die).
Another nice thing about laptops is that they almost all want to be quiet if you'll just give them a chance. I am using a Compaq Presario 12XX class and the keyboard is very quiet--even compare to name-brand quiet keyboards. When you discover your computer mouse is the loudest thing in the room you know you have achieve node editing nirvana.
I don't want to just push Microsoft Terminal Services, as many of you know there's VNC, PC Anywhere, and many other options. So just keep trying until you find something that works. In particular, pick a conservative operating system that isn't so anal that it needs to flush its cache and log every little nitty gritty non-event that happens on your computer. If this is the sort of OS you are running as your "quiet PC" you'll never see the hard drive fall asleep.
There are even thin-PCs you can buy on eBay for a song that uses a Flash RAM for primary storage. And it's not entirely impossible to build a remote booting PC that uses nothing but remote storage spaces. If you manage to find such a PC that could do without a fan it's actually very exciting because then you get better sound and video support. One of the greatest short comings of all remote control softwares like Terminal services is that they don't have the perfect conditions for multimedia use.
If you can get away with it, buy a second hand in-window air-conditioner and a cable extender for your video and keyboard/mouse signal. And leave the PC in a AC'ed storage room. As silly as it sounds a lot of people find themselves struggling to get the most of their PC, and they find themselves trying to fight some of the biggest bottlenecks in their PC. No matter what they do--souping up their PC tend to justify lots of drives or loud fans--more than ever before. And these devices generate tons of heat. It doesn't matter what heat dissipation system people come up with--the room/basement/floor will be cooking without an AC. Most baby-ISP entrepreneurs of the last century can testify to the horror of sitting in their blistering hot basements babysitting dozens of PCs.