HTC Sensation XL hard reset
It’ll permanently delete all your data and customized settings, and will remove any applications you’ve downloaded and installed. Be sure to back up any data and files you want to keep before you do a factory reset.
Performing a factory reset using hardware buttons
If you can’t turn HTC Sensation XL on or access settings, you can still perform a factory reset by using the hardware buttons on HTC Sensation XL.
1. Press and hold the VOLUME DOWN button, and then briefly press the POWER button.
2. Wait for the screen with the three Android images to appear, and then release the VOLUME DOWN button.
3. Press VOLUME DOWN to select FACTORY RESET, and then press the POWER button.
Performing a factory reset via settings
1. From the Home screen, press Apps, and then tap Settings.
2. Tap Storage > Factory data reset.
3. Tap Reset phone, and then tap Erase everything.