Q: Software Problems

Ok, so I have a late 2012 13 inch macbook pro, and earlier this year, the hard drive had crashed and I re formatted it, and just let it be.  Just now, it shut off and when it tuned back on it said "Your mac detected a problem, so it restarted". I normally am really good with computers, but not macs.  Does this mean my hard drive is fried, or my whole computer is fried? or just software.