First method:
- Start by holding down the Power button to turn off the device.
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- Afterwards, press and hold the Volume Up + Power button for a few seconds.
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- When you see a change on your screen release only the Power key.
- Keep holding the Volume Up key until the Recovery Mode appears.
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- Then select "wipe data/factory reset" by using Volume Down to scroll and Power button to confirm.
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- Select "Yes--delete all user data". Use Volume Down button to scroll and Power key to select.
- To restart the phone, select "reboot system now".
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- Congratulations! You have just performed a hard reset operation!.
Second method:
- Make sure your tablet is turned on.
- Afterwards go to Settings and then to Backup & reset.
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- Tap Factory Data Reset and selec Reset Device.
- Choose Erase Everything if you are sure you want to clear all your data.
- Select OK to confirm the whole operation.
- Good job!