Learn how to reset your device to its original factory settings. If you experience performance issues that aren’t solved by restarting or updating your Xperia™ device, a factory data reset might be the solution to ensure optimal performance.
A factory data reset will erase all data on the device memory, including your Google™ account, system and app data settings as well as downloaded apps. It will delete all user-made settings and all user data on the device. If you want to keep any important data, remember to back up the data to a memory card or other non-internal memory.