1. First make sure that you are using the latest version of iTunes before you restore your iPhone.
2. Now connect iPhone to your computer.
3. Select your iPhone when it appears in iTunes.
4. In summary panel click the restore button for your device.
5. Click on Restore again to confirm that you want to restore iPhone
to factory settings.
6. Then delete all data and content.
7. ITunes will download the iOS software files and then your iOS device will be restore.
8. When your iOS device is restored to factory settings it will restart and you can able to see “Slide to set up” welcome screen.
