Upgrade iphone 4 ios from 4.1 to 4.2.1 instead of latest 4.3

Hi,
I have a factory unlocked iphone 4 currently running on ios 4.1.
I want to upgrade it to ios 4.2.1 instead of 4.3 (which itunes defaults to). Trying to restore using Shift key and choosing the ipsw 4.2.1 manually didn't help and threw an error after verifying udpdate with apple.

Kindly help someone?
esi-itdepartmentAsked:
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ecdmonkeyCommented:
I don't believe this can be done.

Apple has stopped signing 4.2.1 which i believe is why the verify fails

Even if the phone was jailbreaked you would have needed to update to and jailbreak on 4.2.1 before 4.3 was released so you could save your shsh blobs.  This would have allowed you to rollback from 4.3 to 4.2.1

As you haven't and no shsh blobs were saved then your only option is to stay on 4.1 or update to 4.3.
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esi-itdepartmentAuthor Commented:
Ecd,

Is it possible if i tell you that the current ios 4.1 is jailbroken and in cydia, i can see "SHSH: IOS 4.1, 4.2.1, 4.2b3, 4.3" written on top. How can i save that shsh? Sorry but i don't have any clue about this shsh stuff. I'll google it while waiting for your reply.

Thanks!
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ecdmonkeyCommented:
Download TinyUmbrella which will allow you to save your shsh blobs from the cydia servers

http://blackra1n.org/2011/04/save-shsh-blobs-for-iphone-ipad-ipod-touch-with-tinyumbrella-windows-mac/ 

then follow the instructions in this link to should be able to install the 4.2.1 using the hold down shift method and running tinyumbrella at the same time

http://blackra1n.org/2011/04/downgrade-ios-4-3-1-to-4-3-4-2-1-4-x-on-iphone-4-3gs-ipad-2-ipad-ipod-touch-4g-3g-how-to-guide/ 

good luck

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esi-itdepartmentAuthor Commented:
Awesome  Man. It worked!
After the upgrade, it wasn't coming out of recovery mode, but i googled it out :-)

Thanks!
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