why is my computer making this sound?

[BaintPall]

for the record i didnt know what forum to put this in so i just chose this one, and also this noise is really bugging me so as soon as im done writing this im turning off my pc. im not sure what this sound is but my computer just started making it 3 days ago.

http://www.zippyvideos.com/8818745716343196/hpim0249/

5 mins later it was making this noise (it hasnt made this one since though, but its constantly making the first one)

http://www.zippyvideos.com/9938414786343206/hpim0250/

thanks for any help you can give me.

 

[Shumway]

Sound's like a screwed fan to me

Take the side panel off and you will be able to tell better where the sound is coming from.