Finding corrupt files on my computer?

So I'm having problem with my iPhone 6 app playing music. It plays at the most 1 or two songs and crashes. Most the time it crashes immediately upon opening. I have tried everything for a simple non techie would do. I even took it to the Apple store for help. They and online told me I have corrupt music files on my computer but the same music plays just fine on my MacBook and my iPod Nano.

This article explains the step-by-step process to restore the phone:
https://support.apple.com/...s/HT201252

  • Why is this world so corrupt? Imagine all the people dying of deadly diseases and suffer every day while others are complaining about how their iphone battery doesn't charge quick enough… like people say "that's life"… Why? That's an awful, awful difference in the quality of life and no one can change it but why is it so darn unfair?
  • Why does my Computer take forever to copy files to my Desktop now? My computer was working fine until yesterday. All of the sudden it takes 2 hours to copy 20 videos from my iphone to my computer. I do this All the time and it takes no longer than 20 secs to copy the files to my desktop. But yesterday and today it's been taking up to 2 hours. I have windows 7 and an HP computer. It's practically a brand new PC.
  • Where are my backed up iphone files (photos) in my computer? So I just wanted to plug in my iphone 5 to my dads computer (its a pc) so i could download some of his music lol but it made me back up my iphone so i was like ok ya whatever, but now i'm concerned because my plan was to back up my iphone, and then delete everything off his computer… I just have photos and videos and such that parents shouldn't see lol so does anyone know where these files are?
  • Opening picture files on computer? I'm struggling to open certain picture files from my email on my computer. The picture was sent from my iphone. When I try to open it it appears to fly to the left of my screen.