all I do is watch movies on my living room pc. the thing is so loud it's driving me crazy. I have replaced the power supply to an earthwatts quiet so i'm good there. The cpu fan is loud and i want to replace it. If someone has personal experience with a cpu fan or a cpu that comes with a queit fan i would love to hear about it. my cpu is about 4 years old so a new one would be fine anyway.
i think you already know what you should do ask at the store or read the package stay away from the sink fans that come free with the processor after market fans that claim to be more quiet are best you may have too many fans...try to keep it too just cpu fan and one power supply fan...the power supply fan should move the air out of the case on it's own good luck
There are a few quiet coolers you could go with. Here are a couple http://www.ncix.com/products/index.php?sku=30009&vpn=NH-C12P&manufacture=Noctua http://www.ncix.com/products/index.php?sku=12760&vpn=XP-90&manufacture=THERMALRIGHT and this fan http://www.ncix.com/products/index.php?sku=28452&vpn=NF-B9-1600&manufacture=Noctua These will be very quiet.
I would recommend using a Thermalright Ultra-120 for that CPU, the Pentium D is about the hottest running desktop PC chip ever made. The fan I would most recommend for it is a Scythe SFF21F.