HTC Desire C stopped working after factory reset
If your phone is not starting anyway try performing hard reset using hardware buttons


Performing a factory reset using hardware buttons


  Note: All your data will be lost.


If you can’t turn HTC Desire 700 on or access settings, you can still perform a factory reset by using the hardware buttons on HTC Desire 700.

Important: The Fast boot option in Settings > Power must not be selected.


Remove the battery, wait for a few seconds, then reinsert the battery.
Press and hold the VOLUME DOWN button, and then press and hold the POWER button.
Wait for the screen with the three Android images to appear, and then release the POWER and VOLUME DOWN buttons.
Press VOLUME DOWN to select FACTORY RESET, and then press the POWER button.



  If doing the above doesn't help you should reach your nearest htc service center