• It's time to check your firewall settings if your iPhone won't sync with iTunes. Go to your Windows start menu, or go straight to the 'Ask Me Anything' search area in the lower left-hand corner of the screen if you're using Windows 10. Type 'firewall.cpl' into that box. You'll be taken to the Windows Firewall screen as a result. Allow an app or feature to pass across the Windows Firewall.
• Scroll down until you reach iTunes in the list of apps. Make sure the box next to iTunes is checked. Both the public and private sectors should do the same. Click those boxes if they aren't already checked, then choose Change Settings.
• It's possible that you'll have to uninstall and reinstall iTunes.
• On a Mac, go to the Apple menu and select Software Update to check for operating system software upgrades. On a PC, go to the Windows menu and select Settings, then Update & Security.
• After you've updated your iTunes and operating system software, restart your computer (if it hasn't already) and try to sync your iPhone to iTunes again.

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