Lenovo A706 hard reset dual SIM phonesave everything. Back up your data.
1. Remove battery. Be sure to charge your battery before doing a hard reset
2. Insert battery. Press both Volume UP and DOWN buttons and press power together for 10 seconds.
3. When the recovery menu comes up release all buttons.
4. Highlight Wipe data / Factory reset using Volume down key. Press power to select.
5. Highlight Yes -- delete all user data and press power button to confirm. All data will be lost!
6. Wait until the phone finish the hard reset.
7. After the menu displayed again press power to reboot phone now.
the soft way:1. From the Home screen, press the Menu Key and touch Settings.
2. Touch the Privacy
4. Touch Factory data reset.
5. Touch Reset phone.
6. Touch Erase everything.