It is not Luck. It is happenstance.
Statistically, it is unlikely that the sound card and the Hard drive would both fail after two years of use. So we* would suspect that the motherboard has a defective component.
In a normal environment, any component failure on a motherboard indicates a defect in manufacturing. However, the manufacture will assume there was user abuse, so they limit the warranty period. Unless both failures are related to something you did, the motherboard is a lemon.
The hardware error messages of Windows are as accurate as they ought to be. Some additional testing is needed to confirm the hardware error. General practice is to try the suspect item, the hard drive in this case, in a computer that is know to be reliable.
FYI, hard drives should have a warranty of fie years for normal usage. Did you try to contact either Gateway or the OEM of the drive? Have you verified that the hard drive really is defective?
What I am trying to say is that you may have a bad motherboard. A new drive will not fix the problem. But the drive you selected is a good choice. Nice to have a spare drive. You will pay more than that just to have a Technician look at it.
If the new drive solves the problem, please come back and tell me I was wrong. I will be glad to know.
* 'We' here means others have already made this observation before me. In your case 'we' suspect component is the south-bridge, or one of its dependent components. As for me, I am a retired silicon-Valley Super Senior Technician and most of what I learned was from other people.