Hard Drive or Graphics Card Malfunction?

I bought a used PC and reformatted the drive, replaced the graphics card as well as the RAM, and for the first handful of months everything was fine. Shortly thereafter, My PC started making i suppose you could call it a cross between a grinding nose and/or a fan working overtime. The thing is, it only starts happening when I go to process-heavy websites (multimedia, photos, videos, pop up ads. etc.). For example, if I hang out at merriam-webster.com and look up one word after another for about 10 minutes at a fairly brisk pace, the transitional processing time from one page to the next or the loading time of the ensuing page slows down to a crawl.

I suspect that the noise is either my hard drive or my graphics card's fan, but I can't be 100% certain. How can I pinpoint why this is happening and where it's coming from?

 

Get a used kitchen roll tube and hold it to your ear like a stethescope. Block your other ear and move the open end of the tube around the inside of the case near the two suspected components.

 

it's more likely to be a fan
in most graphics card driver software ( ati's catalyst control center for example ) you should be able to vary the graphics card fan speed if you adjust this to full it will give you an idea if it's that fan thats causing the noise

on a side note
pay close attention to the CPU fan if that one stops for any reason it might take the CPU with it

i doubt if the hard drive is causing the noise