To hard reset a ZTE Blade C310' Please follow the instructions below.
- Turn off your ZTE Blade C310
- Press and hold Volume Up button together with the Power button at the same time.
- Release both buttons when the recovery Manu appears
- Use the Volume buttons to scroll up and down through the Recover Manu.
- Use the Power button to select of confirm action.
- Press the Volume down to scroll to "Wipe data/ factory restore" and press the power button to confirm
- Scroll down to "Yes---delete all user data"using the volume down button to scroll then the power button to confirm.
- Wait until you see "Wiping complete"
- And then press the Volume up to scroll to "Reboot now" and press the power button to restart the phone.