IOS – iPhone 4 cannot restore to iOS 5 in DFU mode

To enter DFU mode:

1. Make sure the phone is on and iOS fully loaded, and iTunes is closed.
2. Plug the phone into your computer using the Apple proprietary cable.
3. Once plugged in, turn your phone off by holding the power button.

4. When the phone is completely powered down, perform the following sequence:

   1. Hold the power button for 3 secs.
   2. Without letting go of the power button, press and hold the home button for 10 secs.
   3. Without letting go of the home button, release the power button for another 10 secs.

Ignore what's happening on your screen, just time the sequence. If you are not succeeding, then you are not timing the sequence properly. There is only one way to enter the device into DFU mode. The one provided by Redsn0w is the correct one.

I'm able to restore iOS 5.1.1 on my phone using sn0wbreeze. I'm posting the details here in case someone else encounters the same problem.

Initially I used redsn0w to create a custom firmware file but it failed to restore (with errors mentioned in the question and others like error 14, etc.).

Then I used sn0wbreeze to create a custom firmware stitched with my shsh blobs and iTunes restored it without errors.

Here are the steps I followed:

• Downloaded a firmware that i wanted to restore (5.1.1 in my case).
• Added my shsh blobs for that firmware using iFaith mode in sn0wbreeze.
• Created the custom IPSW in sn0wbreeze and stored it on my desktop.
• Put the iPhone in pwned DFU mode. Use iREB or redsn0w to get into the pwned DFU mode.
• Used the custom ipsw file to restore in iTunes.

I don't know if these things count, but during the process my antivirus was disabled and I had commented out any gs.apple.com lines in my hosts file.