I doubt your SATA is faulty.
Is this a PC sold to you as a unit? Or one you have assembled yourself? If you've assembled yourself, you'll have to try swopping out each component to see which one is giving you problems (and hope that a workshop can help you). If it's sold to you as a unit, take it back and say "FIX".
A brand new PC should not give you any problems. And one that gives problems from day one, will always give you problems until you get rid of it. I would suspect your MOBO. Have you done any memory tests and burn-in tests? The ultimate boot CD has a lot of good test utilities....
Since you have problems with your hard drive, and then your video card, the common thing connecting it all together is the mobo. I've had more mobo failures than anything else.....
my 2c