This tutorial is addressed EXCLUSIVELY to iPhone 4 owners, so it does not work on any other terminal. This method was tested by developer of the application and a few other people, it worked for them but I have no way to test it because I only have SHSH for iOS 4.0.2/4.1. This tutorial is ONLY necessary for those who have a coded iPhone 4 and need to keep the baseband version to be able to use ultrasn0w on iOS 4.1. You can find the original tutorial here.
Take these steps OWN RISK!
The tutorial NO LONGER WORKS since the release of iOS 4.2.1!
Step 1
Download TinyUmbrella 4.1.3 from here: Windows, Mac OSX, Linux.
Step 2
Download iOS 4.1 for iPhone 4 by here.
Step 3
Connect the phone to the computer, close iTunes and open TinyUmbrella then press the button "Start TSS Server".
Step 4
Look at the screen "log"(the one with a lot of text) and check to see if TinyUmbrella has displayed any errors. If there is an error, restart the process because if you continue, it is very possible that your baseband will not be protected during the update and you will reach the new baseband for which there is no decoding solution.
Step 5
Open iTunes and restore to the iOS version you downloaded in step 2. Hold down the shift key while pressing the button Restore to select the version of iOS downloaded by you, if you don't then do this process IT WILL NOT WORK!
Step 6
Near the end of the process, iTunes will display an error 1004 and the following texts: "The iPhone could not be restored. An unknown error occurred (10044)." ; "iTunes has detected an iPhone in recovery mode. You must restore this iPhone before it can be used with iTunes.". PRESS "OK" so that iTunes no longer displays the errors, then go to the next step.
This error is very normal because its display means that iTunes failed to update the baseband. In short, if you get error 1004 then the process worked, and if you don't then the process didn't work.
Step 7
In the TinyUmbrella screen you will have a button "Kick Device Out of Recovery", press it and the phone will reset and exit Recovery Mode, then you will be able to activate and use it without problems.
If the Dev Team does not release an update for ultrasn0w, then this tutorial will have to be used absolutely every time you restore to iOS 4.1.
