A factory reset will restore your phone to the settings that were configured in the factory. All of your personal data from the internal device storage, including account information, the system and application settings, and any downloaded applications will be erased.
Important: Back up your personal data before performing a factory reset.
Factory resetting the device
1. Menu > Settings > Device > Device information > Reset Phone
2. When prompted, tap RESET. The device will reset to the original factory settings, and then restart.