IOS – Downgrading to ios 4.1 from ios 5 without shsh

Restoring to 4.2 is not possible unless you had your iPhone jailbroken when 4.2 was the current version and saved Apples signature with this.

But if you only want back to iOS 4 you might still have a chance, because as far as I know 4.3.5 images are still being authenticated by Apple.

So you can try and download the 4.3.5 image (just google for it), and hold alt while clicking restore in iTunes. It will ask you with which file you want to restore.

Select the downloaded file and unless an error pops up (which might be the case if Apple decided not to allow installations of 4.3.5 anymore) you should be running iOS 4.

(Also if you do this, you should do it soon, Apple won't authenticate 4.3.5 images forever.)

If you have your SHSH's saved for 4.3.3, then you should be able to get back to 4.3.3 with some help of TinyUmbrella (it also has a button to get out of recovery loop, maybe you can try that?)

If you don't have your SHSH's saved, there is no way you can get back to 4.3.3 (or any firmware version for which you didn't save your SHSH's, for that matter...)

Official download links are to the right of this page: http://thefirmwareumbrella.blogspot.com/