Please make it STOP!

I have recently purchased an Hp Pavillion p6102f with the AMD Phenom II X4 925 2.8GHz processor. Since the day I purchased it, I have been tormented by a high frequency whistle/whine almost exactly like a mosquito whine. At first I thought it may have been one of the cooling fans..GPU, PSU CPU and did a 'finger stop' on each one in turn. Noise still there. Tried disconnecting the HDD by unpluging the power cable. The noise became quiter and more intermittant, but still there. I have contacted HP's customer no-service by phone and support forum and even called a few local repair shops, but HP says there is no problem and the repair techs say that they didn't hear the noise or they refunded the bench fee (imagine that) with defeated looks in thier eyes. This noise is driving me insane! Help me make it stop! Or at least understand why.

IF this isn't posted in exactly the right catagory.. I fit best as I could

Base processor
Phenom II X4-925 (D) 2.8 GHz (95W)
4000 MHz HyperTransport 3.0
Socket AM3
Chipset
GeForce 9100
Motherboard
Manufacturer: Pegatron
Motherboard Name: M2N78-LA
HP/Compaq motherboard name: Violet-GL8E
Power supply
300W
Memory
Component Attributes
Memory Installed 8 GB

Hard drive
750 GB SATA 3G (3.0 Gb/sec) Western Digital I think
7200 rpm

Modem
PCIe internal modem
Video Graphics
Radeon HD4650
1 GB memory
I/O Ports: HDMI, VGA, DVI-I (dual-link and single-link)
Sound/Audio
High Definition 8-channel audio
ALC 888S chipset
Network (LAN)
Integrated 10/100 Base-T networking interface
Memory card reader

Is this what you need?

Hm. Yeah, like I said, I can't be sure, but my guess is that you may be looking at a power supply issue, because like you said, it fluctuates with the load you put on the machine, and you said it lessened when you disconnected your hard drive. I may be wrong, but if it were me, without looking at it, I'd probably start at the power supply.

If you don't have the slimline model, and if it can use a standard ATX power supply, this supply is decent and should be good for a budget.

http://www.newegg.com/Product/Prod [...] 6817139008

But check with HP to see if it accepts a standard ATX power supply.

Usually its the power supply. Try another one and see if the noise goes away.

If not you are going to need to try and pinpoint where the sound is coming from
does it make it when you first turn on the computer?

It is coil squeal and it is coming from either the psu or the mainboard. In this case it is most likely the board and in that case it needs to be replaced.