WARNING! By factory resetting your phone, all your personal data on the phone’s internal memory will be deleted, including media files and ringtones, downloaded content, apps, contacts etc. Data located on the SIM and SD cards won’t be affected but all the settings will be restored to factory values.

NOTE: Before you reset your device you can check this thread for instructions on backing up data, and this thread for a guide on restoring data.

Factory Reset via Settings:

  1. Open “Settings”
  2. Access “Personal” and tap “Backup & Reset”
  3. Optionally, turn “Back up my data” and “Automatic Restore” ON or OFF
  4. Tap “Reset phone” and in case your device is protected by a lock screen, enter your PIN/password
  5. Optionally, choose to “Erase SD card” as well
  6. When ready, tap “OK”

Factory Reset via Android Recovery:

NOTE: If your phone crashes, freezes, or otherwise it prevents you from resetting it using the method above, alternatively you can try resetting the device via Android Recovery.

  1. First make sure the phone is turned off
  2. Then press and hold “Power” and “Volume down” at the same time
  3. Release “Power” when the phone vibrates
  4. From the “hTC download” screen release “Volume down” as well
  5. Navigate the menu by pressing “volume down” repeatedly and highlight “Reboot to bootloader”
  6. Press “Power” to select the highlighted option
  7. Next, highlight “Boot to recovery mode” and press “Power”
  8. At the “No command” screen, press and hold “Power” and “volume Up” at the same time
  9. Release the buttons once in Android Recovery
  10. Navigate the menu and highlight “Wipe data/factory data reset”
  11. Press “Power”
  12. Highlight “Yes – delete all user data” then press “Power” again to confirm
  13. Once done, ensure “Reboot system now” is highlighted and press “Power” one last time

See More: HTC U12+: Factory Reset via Settings or Recovery