In order to hard reset a BenQ T51, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
BenQ T51 device will be brought back to the default configuration of a brand new device.
1. Switch on the phone.
2. Put this code into your phone's Dialer - *#9999#
3. Confirm the operation by pressing the Call key.
4. The phone will now restart. That is all, the hard reset is complete.