Odd "power off" noise while using the computer

[aliensRreal]

Hey everyone,

I installed Vista a few days ago and ever since then my machine has been making an odd noise every so often. The noise is similar to the sound made when the computer power's off, no not the Windows sound, the sound the computer makes. I have no clue what is making this noise, but it is frightening. If anyone has any suggestions on narrowing it down or a cause I would be grateful.

 

[Danith]

are you sure it's not the hard drives spinning down for power saving?

 

[aliensRreal]

I suppose that makes sense, after all one is mainly for just storing stuff so it isn't used much.