Change the iTunes Backup and File Location in Windows 10

Change the iTunes Backup location

Original folder for iTunes backup:
C:\Users\username\AppData\Roaming\Apple Computer\MobileSync

New destination folder:

From DOS prompt execute command:
Mklink /J “C:\Users\username\AppData\Apple Computer\MobileSync\Backup” “E:\MobileSync\Backup”

Change the iTunes file location

Open iTunes on your PC.
Select Edit and Preferences.
Select Advanced and Change.
Select the drive or location where you want iTunes to store your media.