How to Back Up Your iPhone to iTunesby KR Knowlin ; Updated September 28, 2017
By default, iTunes is set to automatically back up your iPhone before each sync. This ensures that your data will not be lost in the event of a system malfunction or interruption. ITunes also gives you the ability to manually create iPhone backups whenever you want, regardless of whether or not you want to sync the device.
Connect the iPhone to your PC with the dock connector cable. ITunes will open.
Select your iPhone's name under "Devices" in the left sidebar.
Right-click the iPhone's name once it's selected.
Choose "Backup" from the drop-down menu.