1. Switch of the tablet. If the device freezes, you can use a reset hole under the memory card reader cover.

2. Press and hod: Volume Up + Volume Down + Power buttons.

3. In the Recovery menu, use the Volume Down button to move the highlight and the Volume Up to select.

4. Choose one by one: "wipe data/factory reset", "Yes -- delete all user data" and finally "reboot system now".