How to Fix iTunes Error 1004?
So you have an iPhone 4 or iPhone 3GS, running iOS 4.0.1, with SHSH blobs saved on Cydia, and you want to restore your iPhone again to iOS 4.0.1. Now that Apple has stopped signing iOS 4.0.1, you wont be able to restore your iPhone 4 on iOS 4.0.1 by simply pointing iTunes to iOS 4.0.1 ipsw file. Because if you do so, iTunes will throw an error: "This iPhone (your name) could not be restored. This device isn't eligible for the requested build."
Now to fix this error, you will have to make a couple of changes in your system's "host" file, by pointing it towards Cydia server instead of Apple's. Also this is not it, you may also receive another error during restore: 1004, or 1015 from iTunes.
Fix iTunes 1004 Error Tutorial
Preparation: Download iOS 4.0.1 ipsw firmware for iDevices; Go to DFU mode. Here we take iPhone as an example.
Step 1: Connect your iPhone to your PC and switch off your iPhone. Start iTunes and Hold iPhone Power and Home buttons together for 10 seconds.
Step 2: Release Power button by holding Home button until your PC recognize a new USB device. Make sure that you have your SHSH blobs saved on Cydia for the firmware version you restoring or downgrading to.
Now Navigate to C:\Windows\System32\drivers\etc\ and locate "hosts" file. Open "hosts" file in notepad and add "18.104.22.168 gs.apple.com".
Step 3: Now to restore your iPhone to the firmware, Click on phone icon from the sidebar in iTunes and hold left "Shift" button on Windows and then click on "Restore" button in the iTunes and then release.
Well, that's all, now just sit back, iTunes will do all rest things for you. And in the process iTunes will probably throw 1004 or 1015 error at you, but just ignore it.
iTunes is a useful apps for iDevices, you can copy iPad to iTunes free for playing iPad music and movies.
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