Q: iPhone keeps restarting during desktop/iTunes restore backup

So about a month ago, a made an iTunes backup for my iPhone 5S. after which I completely factory reset it, but recently I forgot that I needed something from the old backup, so I went into the iTunes application and did all the steps blah blah blah. and then during the restore progress, my iPhone will just randomly restart and then my iTunes will pop up with a message saying something on the lines of "iPhone disconnected, restore has stopped" I've checked my iPhone and whatnot and my iTunes is also up-to-date as well as my iOS. What is wrong? Is there something wrong with the actual components inside or something?

Any answers would be appreciated as the files from the previous backup were VERY important