HTC HD Mini PB92100 Hard Reset
Performing a factory reset using phone buttons:
With your phone powered off,
press and hold the VOLUME UP and VOLUME DOWN buttons
While holding the volume buttons, press the POWER button briefly and then release it
When you see a warning message on the screen, release the VOLUME UP and VOLUME DOWN buttons
Press the VOLUME UP button to perform the reset, or press any other button to cancel the reset
