Selling your Android phone? want to delete everything on your Android mobile? or want to start again with a clean slate, then you may want to reset your Android phone to factory settings (default settings). Also if you have somehow messed up your Android phone’s software then a simple factory reset can bring it back to life.
Reset your Android Phone
From the Homescreen, Go to Settings-> Privacy –> Choose Factory Data Reset under personal data –> Reset Phone.
This will erase all data on your phone including all application data.