step 1 : Firstly hold down the Power rocker for a short while in order to turn on the device.
step 2 : After that, go the Menu and find and select Settings.
step 3 : In the next step choose Backup & Reset and tap Factory data reset.
step 4 : Then choose Reset device and select Erase everything to confirm the whole operation.
step 5 : Well done! You have just performed a hard reset operation!
step 1 : First of all switch off the device by pressing the Power button.
step 2 : In the next step hold down Volume Up + Power button for about 10 seconds.
step 3 : You can release held keys when you see the Android Robot.
step 4 : To enter the Recovery Mode hold down the Power key for a short while.
step 5 : From the menu choose “Wipe Data/Factory Reset” by using Volume buttons to scroll and Power button to select options.
step 6 :Tap “yes” to confirm the operation if you are certain you want to clear all your data.
Use the Power button to accept option “reboot system now”.
done and Good job!