In order to hard reset a DEXP X355 Zenith, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
DEXP X355 Zenith device will be brought back to the default configuration of a brand new device.
2. Next, press and hold the Power and Volume Up buttons simultaneously. Release them when the DEXP logo appears on-screen.
3. In case the Android logo appears, press the Power and Volume Up buttons simultaneously again.
4. Afterwards, use Volume buttons to select and Power button to confirm the wipe data/factory reset option.
5. A new menu will open. From it, select Yes - delete all user data. Again, confirm with Power button.
6. Now select reboot system now using Power button. Done!