What you need to do is pinpoint the source of the noise first. Open the
case and listen inside to see what you can find. To open the case, look
at this page: http://home.ptd.net/~don5408/case/#5
It could be a processor fan. Either this fan or the hard drive is a
very easy replacement. If you locate the noise, we can help you replace
the bad item and save you money to boot. Let me know what you find.

Mike

You're welcome. If you feel more comfortable, unplug the system then
take off the case. I usually leave mine plugged in when I remove the
case, but that's just me. You could always touch the metal case to
ground yourself if you want. Since it is open, it might not be a bad
time to take some compressed air and blow out all the dust. Plug it
back in, start it up, and see if you can hear where the noise is coming
from.

Mike

For starters, I found this little bit of information on the IBM site
for your 2174:
http://www-306.ibm.com/pc/support/si...chineind=67511
If I was you, I would take a look and copy anything that you think you
may want in the future. There isn't much there, but I'm sure IBM will
pull it soon. I wish they would have at least kept the HMMs available
to Aptiva owners. I have downloaded a few of the manuals, but not the
2174.
The easiest way to find a replacement fan is to take it out and take it
with you to the stores. If I remember correctly, my 2153 only had a
clip holding the fan onto the processor. Make sure that you don't move
the processor too much or you might have to apply new thermal compound
to it. The main thing is that you want to get the right power
connections. You may have to purchase an adapter to hook the power up
to your existing power line. If you know the type of your motherboard
(my 2153, made in 1998, is a Socket 7), you can order online. I found a
new fan for my 2153 for $5 and an adapter for $4 at
http://www.directron.com/cpu---coolers-cpu-coolers.html
Otherwise, the store should be able to match one up for you. Either
way, it should be pretty inexpensive to buy one.
I hope that helps. Let me know if you have other questions.

Mike

Not sure if you have replaced the fan or not, but I found out that you
have a slot A processor. You can find a fan for that at this address
for only $1: http://www.directron.com/slota1.html