You have a problem with your device or you want to reset your device, you may use factory reset.
Factory reset will erase all personalized settings and data from your device's internal storage. And factory reset cannot undo.
PM351
Navigate to Settings > System > Advanced > Reset options.
Tap Erase all data (factory reset).
Please be aware that factory reset will erase all user data. Tap Erase all data to start the factory reset.
Tap Erase all data again to confirm the factory reset.
Press and hold following button combination simultaneously when turning on the device.
After short vibration, release the buttons. Now your device is entered Android Recovery mode.
Using the keys below, select Wipe data/factory reset
After wiping the data, select Reboot system now.