I just bought a used 8310 curve. The previous owner left all of his info on it including email accounts, address contacts and web links. I wanted to reset to factory settings like a new BB. If I wipe the handheld will this remove any necessary operating applications? Will I have to download the 4.2.2 operating system? Should I just delete each application one at a time? I have tried to delete the old emails but I cannot. Please help. I do not want to dammage the operating system.