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Downgrade iOS 4.3 to 4.2.1, 4.1 on iPhone 4, iPhone 3GS, iPad, iPod Touch?ipad applica


January 19th, 2011   

iOS 4.3 has been released and here is how you can downgrade from iOS 4.3 to iOS 4.2.1 or iOS 4.1 for the iPhone 4, 3GS, iPad, iPod touch 4G, 3G and Apple TV.

Downgrade iOS 4.3 to 4.2.1, 4.1 on iPhone 4, iPhone 3GS, iPad, iPod Touch?ipad applica,NOTE: This guide will only work if you have SHSH blobs saved for the respective firmware you downgrading to.

Step 1: Download the required old ipsw firmware files.

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

Release Power button but keep holding the Home button until your computer recognizes a new USB 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 Sauriks server. To do this:

line as shown in the screenshot below:

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 4.2.1 or 4.1 firmware file. Select the desired ipsw file and click on Open to restore your iOS device.

Now sit back and enjoy as iTunes does the rest for you. This will involve a series of automated steps. Be patient at thisipad application download stage and dont do anything silly. Just wait while iTunes installs the requested firmware on your iOS device. Your device screen at this point will be showing a progress bar indicating installation progress. Once done, it will reboot automatically.

Now in some cases while restoring to iOS 4.2.1 or 4.1, iTunes might throw 1013 error at you. This is normal, just ignore this error as the firmware has already been successfully installed on the device.

Incase of the above mentioned error, your iPhone, iPad or iPod touch will be stuck in Recovery Mode, showing that Connect to iTunes screen.

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.

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