Iphone 4 Update Erro 2


please help me to solve my problem, iPhone 4 come with for some apps not working, i try to update with iTunes but its showing error occurred 2,

have try to change usb cable port and pc but stull same problem

also i have try to flash with 3U tool but its stoped at 80% (basband) error (-1) also i have try to dfu mode tis show Verifiy AMRError need soluton kindly help me to solve my problem