restoring and updating my iphone 6 but error code comes up

i have tried restoring and updating my iphone 6 through itunes but it just gets to the last part (firmware) and gives up. its says error 9 accuried. but i have researched how to get passed of error 9 and i have restarted my phone, the computer, done updates on the computer, turned fire wall and anti virus things off and also ttried different USB cables and computers. someone please help me. i put a brand new battery in the phone also and all it wants is to connect to itunes to do its update and restore. PLEASE help i have no phone and have been working on this for 5 days traight now and cant find a solution as to why its not working!!?!?!