Hard Reset HTC Desire VC

First method:

1. Switch off phone.
2. Press and hold Volume Down + Power button.
3. Release when three Android images appears.
4. Find and pick it"FACTORY RESET" to browse use Volume buttons, and to choose option Power button. 
5. After this operation phone will reboot.

Second method:

1. Go to Menu thenSettings and then to the Backup & reset.
2. Find Reset phone and select it.
3. Mark Erase all data if u want delete all media from device.
4. Press the OK.

WARNING !
Hard Reset will erase all of your data
All described operations you are doing at your own risk.