HTC 7 Pro Factory Data Reset

Tap start screen > about phone > reset your phone
Hard Reset:
This method applies to all the HTC phones (HTC HD7, HTC 7 Trophy, HTC 7 Mozart)
running the Windows Phone 7 OS.
If you can turn off the phone do it. For unresponsive or frozen phone, remove the
battery and put it back again after few seconds.
1. Press Volume up button and hold then press Volume Down button and hold and
then press the power button (briefly) to switch the phone on.
2. Keep holding the volume up and volume down buttons until you see a reset
screen option.
3. Now follow the instructions that will show up on your mobile screen to factory
reset your phone