HTC DESIRE 820 HARD RESET SOLUTION

 If HTC Desire 820 has a persistent problem that cannot be solved, you can perform a factory reset or hard reset. A factory reset reverts the phone back to its initial state — the state before you turned on the phone for the first time.

The following will be removed from the phone when you do a factory reset:

•     Your Google Account

•     All accounts you've added in Settings > Accounts & sync and the data associated with these accounts

•     Personal data that you've created or synced to the phone such as your profile, contacts and more

•     System and application data and settings

•     Downloaded game and  apps

• Files such as your music, photos, videos, and documents can also be deleted from the storage, if you chose to do so.

Be sure to back up any data and files you want to keep before you do a factory reset.
Note: A factory reset may not permanently erase all data from your phone, including personal information.
Performing a factory reset from settings

   1.  Go to Settings, and then tap Backup & reset.
   2.  Tap Reset phone.
   3.  If you want to delete media, documents, and other data from the phone storage, select Erase all data.
       To also delete media and other data from your storage card, select Erase SD card.
   4.  Tap OK.

Performing a factory reset using hardware buttons

If you can’t turn HTC Desire 820 on or access settings, you can still perform a factory reset by using the hardware buttons on HTC Desire 820.
Important: The Fast boot option in Settings > Power must not be selected.

   1. Press and hold the VOLUME DOWN button, and then press and hold the POWER button.
   2. Wait for the screen with the three Android images to appear, and then release the POWER and VOLUME DOWN buttons.
   3. Press VOLUME DOWN to select FACTORY RESET, and then press the POWER button.