yesterday I wanted to update both my iPad and iPhone to iOS 8.0. I usually do this wireless via the phone settings, but yesterday I chose to update from iTunes. So I connected my iPhone 5 to my PC, made a backup and started downloading the newest iOS.
After 30 minutes of downloading it told me something like "The firmware is damaged" and asked me to disconnect the phone from the PC and plug it in again. I've done that, and tried it again. Another 30 minutes later (the downloaded ISPW wasn't saved anywhere, iTunes just disregarded it) the same error popped up.
So I went ahead and downloaded the correct ISPW (iPhone5,2_8.0_12A365) via my browser, which worked. Next I shift-clicked the "Update"-button in iTunes, chose this .ispw and started the update. After fixing a error 3194 (by manipulating my PC's hosts-file) I got my iPhone to start updating for a couple of seconds. Then iTunes terminated the update with an error 14. Now my iPhone is stuck in restore mode and every time I try to update it, it either gets stuck while "restoring iPhone-software" at ~10% (I've been waiting for 20 minutes, the progress bar didn't even move a bit) or stops with the error 14 again.
With my luck I've tried the same thing with my iPad mini (Retina)... Same result, device is now stuck in restore mode and won't update due to error 14.
I've tried another PC, another cable, another USB port, switching it into DFU-mode (it jumps right back into restore), nothing worked.
I've been trying to fix it for the last 5 hours, but hadn't had any luck so far. I hope someone can assist me.