Is My Hard Drive Broken Or Is It My Graphics Card

[downlikerain]

I just bought and built a computer about 2 months ago.

2500k
8gb ripjaws
HD 6950
MSI motherboard
Spinpoint F3
WIN 7

And when I first got It everything was going fine and then about a week into it my computer would freeze up, Sometimes 15 minutes later and sometimes in an hr or whatever. But only in win 7 on the new drive, But wouldnt on xp on the old drive. I did flash my gfx card which didnt work it just had artifacts so I flashed it back, But I think I did it wrong. So do you think maybe my gfx is the problem but since it utilizes more stuff since its dx11 vs dx9 it freezes and I did flash it on 7 or do you think its my hard drive (I HOPE TO GOT IT IS) Because when theres and sounds when it freezes it has a horrible buzzing sound..do you think I should get a new hd and also do you think I should install xp on the new hd and see what happens

 

[Rusting In Peace]

What power supply are you using?