If this issue is only existent with iTunes, head over to Download iOS Firmware for iPhone, iPad, iPod Touch, Apple Watch and Apple TV. and download the latest IPSW for your device (or any IPSW that is currently being signed (shows up in green text not red)), then when you come to restore using iTunes, hold the shift button (windows) or command button (Mac OS) and then press the restore button, a new window will open, direct it to the .ipsw you downloaded earlier and it will verify and use that .ipsw instead.
I just looked at iTunes on Google , but i can't open , there are some erase tools for us to wipe iPhone ,Thanks. I already wiped the phone with this method, The network connection is bad with iTunes. So iTunes i not a good option for me,
How to Delete Everything from iPhone,iPad,iPod before Selling .