An Unknown error has occurred (-54)

I just bought a new dell computer with windows 8.1 and installed the newest iTunes for my iPhone it wouldn't backup or syn with my phone with out getting "error (-54)", what I ended up having to do is go in to C:/program files/iTunes copy folder iTunes.resources then go to C:/program files (x86)/iTunes copy that folder in to there then restart computer and the error went away I was able to back up and syn my iPhone with windows 8.1.