RAM doesn't make any noise, it's Solid State with no moving parts....
It is definately your HDD, and to be honest I wouldn't say 100% that there was anything actually wrong with it...It's a Raptor, 10000 RPM ultra quick seek times and fast data transfer are what this drive was designed for, Quiet they are not 🙂
I must say that after checking your speck, you have definately not got a Silent PC, do you want one? or do you want fast performance in games, windows and any apps?
These days you have to make definate choices with a large degree of compromise. Silent or Fast, the only way to have both silent AND fast is to go a little extreme with your cooling, like the Zalman TNN (Totally No Noise) Case, which is really a huge heatsink to hold all your parts.
I recently built a Home theatre PC and this really brought home how restrictive or expensive this compromise between performance and noise can actually be.
Some of the things I did to lessen noise were to use Zalman CPU and GPU heatsink and fans, very effective as it allowed me to use a 7900GT 512MB OC and an Athlon64 3700+ with next to no noise...I used 2xSamsung 250GB SpinPoint drives, these babies are silent but not nearly as fast as Raptors.
I still have a bit of work to do with noise/vibration dampening on the case, a Thermaltake Mozart with VFD. Good looking (IMO) but not easy to keep quiet due to the smaller sized case fans...Although some Silicone gromets and washers should help, not to forget the AcoustiPack noise dampening Material Kit that I'm going to fit. This should bring noise down to almost non existant, perfect for a HTPC.
Just keep in mind that a performance Gaming rig doesn't need to be quiet! Just fast ;-)
JKay6969