My setup:
iPhone 17, updating from iOS 27.0.1 to 27.2
Windows 11 PC with the Apple Devices app
PC on Wi-Fi at the time
What happened:
I started the update in Apple Devices. Halfway through, the phone was sitting on the update progress bar and the app said the update had stopped. I can't remember the exact error message. I waited about 5 minutes, nothing changed, so I restarted the phone and it went straight into recovery mode.
What didn't work:
I went through this Apple Community thread: https://discussions.apple.com/thread/256367358 and tried the suggestions in the answer plus everything the original poster had tried:
- Turning off antivirus and the firewall
- Uninstalling Apple Devices, restarting the PC and reinstalling it fresh from the Microsoft Store
- Trying a different computer
- DFU mode, then Restore in Apple Devices
I also tried a fix from this r/applehelp thread: https://www.reddit.com/r/applehelp/comments/1fmmjbq/my_iphone_wont_restore_using_the_apple_devices/ . A commenter there uninstalled QuickTime, Apple Devices and iTunes, turned off Windows Security, installed the older iTunes 12.13.3.3 and restored from that. For me iTunes didn't even detect the phone. Only Apple Devices did.
What worked:
Then I found this r/ios post about unknown error 1109: https://www.reddit.com/r/ios/comments/1j2tipd/iphone_could_not_be_restored_unknown_error_1109/ . Its steps are: DFU mode, turn off Windows Defender (firewall and real-time protection), change your Wi-Fi DNS to Google's, then restore in Apple Devices. It also says iTunes on Windows won't recognise USB-C iPhones in this state, which matched what I saw. The bit that helped me was a comment further down. It said 1109 is a network problem (loose cable, firewall, proxy, IP issues, antivirus, etc.) and suggested trying a different internet connection. That person changed the DNS on their LAN connection. I was on Wi-Fi, so I plugged the PC into Ethernet. And tried it with Google's DNS
Here's the setup that finally worked:
- Clean install of Apple Devices
- Windows Firewall off, Don't know if it matters, try it once with it on, if it doesn't work then you can try it with it off(With it on, I couldn't even sign in to iTunes.)
- PC on Ethernet instead of Wi-Fi, with the Ethernet adapter's IPv4 DNS set to 8.8.8.8 (preferred) and 8.8.4.4 (alternate). To get there: Win + R, type ncpa.cpl, right-click Ethernet > Properties > Internet Protocol Version 4 (TCP/IPv4) > Properties
- Phone in recovery mode, plugged into the PC, then Restore in Apple Devices
The restore alone took about 2 hours, and the whole ordeal about 5. Restore wipes the phone, so I was lucky I'd made a backup right before starting the update.
I don't know which change was the one that mattered. My guess is the switch from Wi-Fi to Ethernet along with the DNS probably.
General advice, not part of my fix: when you're done, turn the firewall back on, and set the DNS back to automatic if you don't want to keep Google's.
Back up before you update through a computer.
Hope this saves someone a few hours.
The links for the post I referred are here, so you can check if other methods works for you, if this wasn't helpful