In order to hard reset a Haier A66, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Haier A66 device will be brought back to the default configuration of a brand new device.
1. Power up the device.
2. Enter Settings and select Restore factory settings.
3. Your device will now reboot and restart. Good job, congratulations.