the hard drive. not a fan. Open your case and listen. If it is the hard drive, you better back it up fast. Its going to die.
Hi. My HDD makes these weird noises, but not all the time. I only use to do it while starting up the computer, but now it does it more. I recorded the noise with my cell phone, but its a .qcp file. Would anyone let me email them the file so they could hear it? Thanks!

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic