Hello,

3 days ago my computer started making very quiet beeping sounds, it happens mostly when I use Mozilla Firefox and Windows Explorer. My impression is that the sound is coming from the motherboard. When I restarted in safe mode the sound disappeared, so after a very long elimination process I discovered that when I change control panel-power options-processor power management settings the frequency of beeping changes as well. Until now I was using balanced settings (min processor state 5% and max processor state 100%), if I choose high performance (min and max processor state are both 100%) the beeping becomes very frequent almost continuous, and if I choose power saver settings (min processor state 5% and max processor state 50%) I don't notice the beeping anymore but of course I don't want to keep using only 50% of my processor. I am using a desktop computer, not a laptop. Except for the annoying sound the computer works normally.

What could be the problem here: the OS (Windows Vista Ultimate 32-bit SP1),
the processor (INTEL LGA Core2Duo E4500 2.2GHz),
the motherboard (ASUS S775 P5LD2 SE/C Intel 945P/ICH7 1066 DDR2/667 PCI-E x16 SATAII GLAN S/B 6Ch),
or something else?