just built my family's new computer, but there's one noise that seems rather odd, just wanted to make sure that it was normal. I have a western digital 120 gb caviar hd w/ 8mb cache and upon turning the computer on it emits a short buzz, the same noise you'd hear if a wire was hitting a moving fan. It lasts for about 1/4 of a second and has me kinda worried. The hd works absolutely perfectly though. Any ideas what that noise is?