How to Reset the Software on an Android Phone
When something’s wrong with your Android phone, and all else fails, you can do the drastic thing and reset all the phone’s software, essentially returning it to the state it was in when it first arrived. Obviously, you need not perform this step lightly. In fact, consider finding support before you start:
At the Home screen, press the Menu soft button.
Choose Settings, and then choose Privacy.
Choose Factory Data Reset.
By itself, the Factory Data Reset option merely resets the phone’s software. The information you have on the phone’s storage (internal and MicroSD card) remains. That way, the pictures, videos, music, and other information saved on the phone’s storage aren’t erased. That is, unless you:
Optionally, place green check marks by any Erase options for the phone’s internal storage and MicroSD card.
Erasing these options isn’t required in order to fix phone problems.
Touch the Reset Phone button.
Touch the Erase Everything button to confirm.
All the information you’ve set or stored on the phone is purged.
Again, do not follow these steps unless you’re certain that they will fix the problem or you’re under orders to do so from someone in tech support.