I have the same problem (on a Win98SE system). The fan usually doesn't
kick in unless I play a particular game that uses DirectX. When I turn
off the game, the fan eventually stops. It's a fairly new system.
The fan noise sometimes happens at other times, and I have to restart to
turn it off, otherwise it will go all day...literally. But, yeah, the
fan noise is DEAFENING! You can't hear anyone talk in the room it's so
loud.
BTW, I use a CPU cooler, and it doesn't help.
When I selected my last computer a few months ago, the shop
had several models setup which you could try out. I put each
one under a pretty good load and listened closely at the PS
fan exit.
The faster the CPU, the louder the total noise. The overall
noise level of the 2.4 gig was quite loud to me. They also had
open units on another bench where you could see the innards.
The faster the machine the bigger the fan.
I decided the 1.3 ghz was five time faster than what I had and
considerably quieter so I selected that setup. It was also about
1/3 the price of the fastest. The faster the CPU the hotter they
run too and I wanted to stay away from using a cooler if possible.
The temps could be viewed in the bios and when I compared them,
the CPU operating temp convinced me to go with the 1.3ghz model.
It's running at 39-42C now without cooling but is noticeably
noisier than my old 300mhz.
My 2?,
BoB