How to hard reset:
Warning! All data will be lost!
1.Power off your tablet
2.Press together volume up + power button
3.Select with volume buttons "wipe data/factory reset" and press power button to confirm
4.Select "yes" and press power button to confirm
5.Wait until format ends
6.Press power button to confirm "reboot"
7.Wait until the tablet restarts
That's it!
Here is video how to do:
