Trying to determine if my hard drive is about to die

I don't know if this is a hardware or a software issue, so I put it in this section. I'm really worried that one of my hard drives is failing, but I don't know for sure. Here's the story: Fed up with Windows 8.1, I decided to go back to Windows 7 Pro. So I copied all my personal files onto my second drive and wiped out the main drive with diskpart and the Clean command. I installed Window 7,...