To restore to factory settings, the steps are as follows:
Go to the menu Settings / Settings
Scroll to the bottom and find the menu Backup and Reset
Then tap to Factory data reset
Tick assumed to be true, then tap the device reset.
Wait until the process is complete reset about 3-10 minutes depending on the amount of data available on phone or tablet.
Once completed, the android will restart itself, if not please do it manually.
The second way that can be taken is to use a secret key
that is * 2767 * 3855 #. With a record you can still access the keyboard.