My computer is making a weird humming noise. And the hum changes pitch so it doesn't always sound the same. I suspect it's my video card because I remember I had to return this one two weeks after I got it when I originally bought it over a year ago. My question is basically, could it be my hard drive? I was under the impression that a hard drive error would have a constant noise, not a changing noise. Also, should I go and buy a new video card because I honestly have no idea why it would be making a noise?