Ok this is a weird problem i've run into. Whenever i start the computer up before I go to the windows screen my computer makes a high pitch noise, when i start windows up the high pitch noise goes away and is replaced with a processing sound I guess you can call it. The weird thing is if I click back on my browser the sound will stop every time I click back. I also opened up Diablo II and in the start screen and lobby the sound would stop but as soon as I went into the game it would pick back up, but less noticeably. I'm hoping this is my cpu, which is an athlon 64x2 4200+.
There's no such thing as a processing sound. That might be the sound of the fans rotating inside. A high pitch noise is usually uttered by a dying PSU. Or maybe a busted cpu cooler fan. Could you give the specs/model of the PSU you're using?
err guys, I know for all of my systems, when in POST the fans turn on at absolute FULL and then dim down to normal after POST, and that older/crapier mobos have had fans that ran on full until OS hand off or something like that...
then again that psu seems like a no name and is dying.
I have the same power supply that came with my APEX SQ-328 case (<--look that up on google and see if this is, by chance, your mid-ATX case). The power supply is the Apex Allied AL-C400ATX.
The noise that the PSU makes is from the capacitors and they sound like a high pitch tinitus whining sound. Almost like an old modem sound or cicadas.
I noticed the problem about a year ago, and I took the PSU out and tweaked/glued the capacitors down; the noise went away. This week, the noise started up again due to the changing weather/barometric pressure/humidity.
It's annoying and it tells me that the filter capacitors are probably not smoothing the power. So I bought a Corsair VX450W.