Annoying Ringing Sound STILL...

Okay, I am still hearing a high-pitched, high-frequency-like ringing sound either protruding from my PSU.

To double-double check all areas of the PC I:

1. Swapped my current Ultra X3 1000W PSU with another Ultra X3 1000W
2. Wired and rewired all of the cables
3. Loosened the mounting srews of the CPU waterblock

And after all of these attempts I still get the sound.

I start my PC and for about 5 minutes am free of the annoying noise. Then I notice it ever so slightly until it gradually gets louder and louder. Ever time the hard drive is in use, or I move the mouse, or type on the keyboard it makes the same sound.

Are you sure its not the mobo or gfx card?

From what I've experienced it is PSU related and it is not good for the PSU. It COULD be a different part of your system but I have yet to hear this sound from a mobo or graphics card, it is more commonly a HDD issue, certain drives just make that sound even though they are fine, try another HDD if you can.
Do you have a PSU from a different manufacturer you can try? If the sound goes away it probably is related to that certain PSU.

Some 965/975 mobos had whistling capacitors. Many used some type of silicon/glue to suppress the noise. Cant find the link, but if do will post.