There are two ways to do a factory reset:

A. To do a factory reset without getting into the Android operating system -

1. Remove your SD card, turn off the tablet, then hold down the power & volume up buttons at the same time.

2. It should boot up to a menu. Use the volume buttons to navigate down to the Recovery option and press the power button.

3. A screen with the Android logo should appear with the words "No Command".

4. Press then release the power and volume up buttons again to bring up another menu. Scroll down to "Wipe data/factory reset" and press the power button, then scroll  

   down to "Yes - delete all user date" and press the power button again.

B. From the Settings Menu -

1. From the home screen, drag down from the top-right side of the screen, then tap the Settings icon.

2. Tap Backup & reset.

3. Tap Factory data reset.

4. Tap Reset tablet then Erase everything to confirm.