Buzzing sound from CPU

[sublime]

Its like a drone buzz/sound. Comes and goes, but is easily noticeable while sitting at computer.

Any ideas?

[tonypaladino]

Could be your hard drive or either the power supply or processor fan. If your hard drive is crapping out you better back it up.

[wonderwes]

Take the cover off your case and listen for it. Make sure all is quiet so you can pinpoint the sound. It is likely the cpu fan, the hard drive, or possibly your video card if it has an exhaust fan on it. It could just be something random in the case vibrating for no reason.

Like the above poster said, always back up your non replaceable data.

[smoore]

*probably* a fan. You can figure out which one by stopping them for a second or two with a pencil eraser