not all deleted files are recoverable to be very simple if you deleted a file you can recover it Juts in one case , no other file is stored in the same place of your HDD that the deleted one was on it ..
BTW download this program & perform a scan & for the files that appears Green you can recover it & if it appear red you can't recover it because you stored another file / folder in it's place in your HDD
https://www.piriform.com/recuva