unsuccessful iOS 8.4 update, iPhone 6 not functioning
I just tried to update iOS 8.4 on my iPhone 6. When hooking the phone up to iTunes on my Windows computer, it said there was an update, so I followed the procedure. the phone is connected via cable to the computer. Now I'm stuck--a picture of a cable with an arrow pointing toward the iTunes logo, on the screen of my phone. No indication of the phone connection to iTunes. The phone is not functioning now. What to do?
iPhone 4S, iOS 8.1