Last Updated: Sep 23, 2015
A hard reset removes all information from your device and returns it to a state just like it has never been used before. A hard reset should only be performed after all other troubleshooting options have been exhausted or if you want to remove all data and personal information from your device.
NOTE: All contacts, messages, emails, third-party applications, and other software and data should be backed up and will need to be reinstalled after performing a hard reset.
To perform a hard reset, tap Start > Settings > All Settings. Then tap the System tab and tap Clear Storage. Follow the on-screen prompts to complete the hard reset. This process will take 5-10 minutes.