Factory reset is by means of clearing our phone data and restore it to default factory settings. If you wish to factory reset your phone, then you can perform a hard reset. This will delete all the data.

This can be done in this way:

 

Go to Settings –> Privacy –> Factory data reset.

 

This method is valid for all the ++Mobile phones. However, many users have experienced problems in resetting the phone using this method. Also, please note that this method only does a factory reset.

Or you can do a Hard reset using a they called hack code: *2767*3855# — Dial this code on your phone. Please note: DO NOT TRY THIS for testing purpose unless you are sure what you want to do. This code does not ask for a confirmation . And lastly you can do factory reset using: *#*#7780#*#* — Dial this code on your phone.

 

This will ask you for a confirmation before resetting. I once try this on my iPhone 5s and first it will ask to confirm if you want data reset, just to confirm only and it works .