Apple Inc on 14th July 2010, released the first beta iOS 4.1 version with updated SDK for iPhone 4, 3G, 3GS and iPod Touch 2G and 3G. However, if you are among the few who downloaded the version iOS 4.1 and wants to switch / downgrade back to the iOS 4.0 version because of incompatibility issues with various iPhone applications, here I will detail it both for Windows and Mac users.

What is new about the iOS 4.1

Since Apple has released the Beta version, downloadable through iTunes; it will not take long for the full version to be released towards the end of the year. The beta version has several improvements to the iOS 4.0; however reported that its current antenna reception issues is not fixed. Here are the primary changes:

  • Revised calculation method for display bars showing mobile signal strength. The graphics of the signal strength bar is also slightly enlarged
  • iPhone’s modem firmware has been updated from 01.59.00 to 02.07.01
  • Camera shutter release and flash buttons now rotate according to the iPhone’s physical orientation
  • Users can now turn off auto spell check while typing
  • Game centre is completely redesigned; keeping in mind future releases, which will be serving more social gaming platform for iOS device users.
  • Gamers can post their high scores and compare scores online.
  • Voice and FaceTime favourites now added in the iPhone applications and can be added from old favourites. This is handy especially when using video chat over Wi-Fi

Downgrade type 1

This method should be done at your own risk, since it may change the baseband and there is a possibility that you will not be able to unlock using the carrier unlock. Ensure you have downloaded the original iOS 4 firware for your iPhone and save it on your desktop. Connect the Iphone to your computer (Mac or Windows) and restore to iOS 4.0 IPSW file using iTunes. You may get a 1015 error but click OK.  Open your command prompt (Mac users open Terminal) and type cd Desktop . / iRecovery –s serenv auto-boot true saveenv fsboot exit. Once done unplug you iPhone and force shutdown and you will be set back to iOS 4.0 when it restarts.

Downgrade type 2

I hope before you downloaded the iOS 4.1 firmware you had saved SHSH blobs (ECID SHSH) files to Cydia server (because the following process will only be effective then); this ensures you can jailbreak from the new firmware iOS 4.1 update will permanently disable jailbreak and ultrasnow software unlock on all gadgets. Windows users: open your notepad by ensuring you are in the administrative mode. Open the file C:\WINDOWS\system32\drivers\etc and add at the end of the file and save the file. For Mac users: open TextEdit and add save file onto your desktop after adding Open the folder/etc with Navigate to Go and replace with the text with the text file you saved on the desktop.

This way you can ensure your iOS is back to 4.0 and wait till the full release to update the iOS firmware.