Hard Reset HTC Desire V

First method:

1. Start by going on Home screen, then select Menu button , after choose Settings.
2. Then SD & phone storage option, and Factory data reset.
3. Select Reset phone, and then you should mark Erase everything.

Second method:

1. Remove the battery from HTC device and shove it after few seconds.
2. Press and hold the Volume down button, and then briefly press the Power button.
3. Hold untill the three Android images to appear.
4. Then release the Volume down button.
5. Press Volume down and navigate to Factory reset option, and then press the Power button. 

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