Hard Reset ZTE Z830 Compel

First method:

1. Make sure, that you are in Home screen.
2. Then from the Home screen press Menu, and goto Backup and Reset -> Factory data reset -> Reset phone.
3. Now enter your password.
4. After that tap Erase everything, and confirm that.
5. Done!

Second method:

1. Power off your phone.
   
2. Next hold and press Volume Up + Volume Down + press and release Power button.
   
3. When menu appear, then release holded buttons.
4. Now press Volume Down to select Recovery option, and confirm that with Volume Up.
   * If Volume Up doesn't work, then use Power button to select.
5. Afterwards choose from the menu option "wipe data/factory reset" using Volume buttons to scroll options, and Power button to confirm operation.
6. Select from next menu option "Yes -- delete all user data".
7. In the end of this procedure press Power button to confirm option "reboot system now".
8. Success!

Third method:

1. Turn off your handset.
   
2. Now hold and press Volume Down + press and release Power button.
   
3. Next you should see menu.
4. From this menu choose option "Clear Storage" using Volume Down to scroll, and Power button to confirm option.
5. To confirm operation press Volume Up.
   
6. Good job!

Fourth method:

1. Switch on your cell phone.
   
2. Afterwards tap this code: *2767*3855# or *983*987#
3. Now you phone will reset and restarts.

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