I have had some internal noise on a home built computer since I built the thing. It sounds like high-pitched but low volume scratching and screetching (never thought I would use those terms when referring to a computer 8O ) that occurs when my hard drive is accessed or turning and also when I use the mouse and scroll with the side bar. I am thinking that it is noise being caught by the embedded sound card with the pc. I have no additional sound card installed. Any thoughts?