I Phone 4G - Downgreade From 4.3.1 to 4.3 / 4.2.1 Or 4.1

NOTE: This guide will only work if you have SHSH blobs saved for the respective firmware you downgrading to.

 If you upgraded to iOS 4.3.1, a you want to downgrade back to iOS 4.3, iOS 4.2.1 or 4.1, simply follow the instructions posted below to downgrade iOS 4.3.1 on iPhone 4, 3GS, to iOS 4.3, iOS 4.2.1, and 4.1

You can downgrade iOS 4.3.1 to iOS 4.3, 4.2.1, 4.1 on iPhone 4, 3GS, . Follow the steps below to downgrade iOS 4.3.1 to 4.3/4.2.1/4.1 firmware using Tinyumbrella andediting Hosts file

Step 1: Download the required old ipsw firmware files. (Download links: iOS 4.3, iOS 4.2.1, iOS 4.1 )

Step 2: Put your device into DFU mode (not recovery mode).

• Connect your iOS device to your computer.
• Turn it off.
• Start iTunes.
• Hold Power and Home buttons together for 10 seconds or so.
• Release Power button but keep holding the Home button until your computer recognizes a new USB device.
• iTunes will now recognize your Device

Note: Your iPhone, iPad or iPod touch screen at this time should be blank (black in color), if not, then you are most likely in Recovery Mode, not DFU mode.

Step 3: Now trick iTunes into thinking that it is watching Apple servers, while in real, we are going to change the address to Saurik’s server. To do this:

• Navigate to C:\Windows\System32\drivers\etc\ and locate “hosts” file.

Mac OS X users can get to “/etc/” directory by going through “Go –> Go to Folder” from Finder.

• Open this “hosts” file in Notepad (for Windows) or TextEdit (for Mac OS X) and add this
• 74.208.105.171 gs.apple.com

line as shown in the screenshot Above
Now simply save this file and you are good to go!



NOTE for Windows 7 and Vista: Start “Notepad” with Administrator privileges by right clicking on “Notepad” app, and click on “Run as Administrator“ option.
NOTE for Mac OS X: Make sure you have full read and write access on your account when you are saving the host file. If it still throws permission error, simply copy the host file to desktop, make the required changes, and then replace it with the original file in “/etc/” directory.

Step 4: Start iTunes, click on your iOS device icon from the sidebar in iTunes. Now press and hold left “alt” (option) button on Mac, or Left “Shift” button if you are on Windows on the keyboard and then click on “Restore” (Not “Update” or “Check for Update”) button in the iTunes and then release this button.

This will make iTunes prompt you to select the location for your iOS 4.3, iOS 4.2.1 or 4.1 firmware file. Select the desired ipsw file and click on “Open” to restore your iOS device.

Now in some cases while restoring to iOS 4.3, iOS 4.2.1 or 4.1, iTunes might throw 1013 error at you as shown in the screenshot below

iTunes should bring up the error 1015, 1013 or 1011 message. Don’t worry, it’s normal. You’ve successfully downgraded your iPhone/iPod Touch firmware.


Step 5

To exit your device from Recovery Mode, download this program called TinyUmbrella (Windows/Mac). Run it and the click on “Exit Recovery” button. Your device will now restart normally.

Now in order to get out of recovery mode, hit the “Kick Device Out of Recovery” button on TinyUmbrella right below the Start TSS Server button or you can also . That’s it!

ANd You Have Done It njoy