Please provide Make/Model of your computer back here to this thread so we may be better to advise you. Also, if your computer came with W10 and you downgraded to W7 to fix your problems, that's often not possible as W7 doesn't work well at all on computers made after July 29, 2016 (W10 anniversary cutoff).
How old is the hard drive you have? Make/Model of the hard drive too please. If it's older than 3 years old, chances are very high it's failed. If you ran Ubuntu in LiveCD mode and it worked, that means you bypassed your hard drive entirely; where you W10 and W7 live. If it worked, that just says your RAM sticks and Motherboard are ok; nothing about your hard drive, and that's why bochane is telling you to test it. If your...