unfortunately home screen has stopped
You should take a look at this thread - It's a different phone, but similar problem. You should try start your phone in Safe Mode, or try to (painfully) get to the application menu and clear the data for the HomeScreen Application. If Safe Mode works for you, I would try deleting apps that you may have installed around the same time as your first encounter with this error message - An app is the most likely cause of this problem. (Because you say you reset your phone, which should clear any apps you installed, I am assuming you reinstalled all your apps).