How to format your HTC One (factory reset)
The following steps show you how to hard reset or factory reset your HTC One
This is pretty self explanatory. Remember that this will wipe the phone so make sure that you have backed up everything you want to keep first!
- Turn off your phone.
- With the phone turned off, press and hold the VOLUME DOWN button, and then briefly press the POWER button.
- Wait for the screen with the three Android images to appear, and then release the VOLUME DOWN button.
- Press VOLUME DOWN to select CLEAR STORAGE, and then press POWER.
- Press VOLUME UP to start the factory reset.