no because none of those things make noise. Im at a loss as to what it could be. Try stopping the power supply fan.... wait, unplug the harddrive on boot, see if it still does it. also unplug he cd/dvd rom drives.

how will i play the games if i unplug the hd tho? the sound is only audible in games

Ok, im starting to get confused. Lets recap this. It makes the sound when you play games, and it started one time when you started your computer. its not the fans. It is likely the harddrive or the power supply.

the sound does not come on when starting the pc up

how many different MODELS (not replacements) of power supply have you used?

antec truepower 850w's and the one i am currently using is an antec neo power 650. Got rid of the 850w because it made a faint screeching noise (noise 1) that the pc shop guys apparently did not hear, maybe i have superior hearing... oh oh, i know why you are confused, the noise when the pc started up once is different to the noise i get in games (noise 3), it was a big long, loud, beep (noise 2) i put to phone up to the pc and called the pc shop who said it was the Power Supply Unit and they did something, they said they changed the Power Supply Unit to a new truepower 850, but i dont believe them, anyway there was no beeep noise after whatever they did (noise 2), but the Power Supply Unit still made the screeching noise (noise 1) i stated earlier. The Power Supply Unit screeching noise (noise 1) is no longer present as i have a 650w Power Supply Unit, but the sound i do get is when playing games and is more of a hissing noise aswell (noise 3). I never used to get this sound (noise 3) when playing games, it only seams to have started after the pc went beeeep (noise 2). Hope the noise numbering system makes it all easier!