I have an iPod 4th generation which is never jailbroken with iOS 4.1 and want to update it to 5.1.1. I downloaded the .ipsw file. On clicking ⌥ alt/option + Restore in iTunes (10.7) and selecting the .ipsw file, I get the following error:
This device isn't eligible for the requested build
I have tried editing the hosts file by adding a # in front of 74.208.10.249 gs.apple.com but the error still persists. Any suggestions regarding this?
Best Answer
Whenever an iOS device is restored, it checks with Apple's servers to see if the version requested is still being "signed". If it is, the restore goes as planned. Right now, the only iOS version being signed by Apple is 6.1.3.
There is currently no way to restore to iOS 5.1.1 without being jailbroken in the past.