After lengthy search, I managed to downgrade my iphone 3GS From three.1.three to a few.1.2 with the brand new iBoot ,whereas I was once in my ECID three.1.three and was once no longer registered on the  saurik server.

1 – Downloaded the firmware three.1.2 for your computer.

2 – Make sure that the iTunes is updated to the latest version

3 – Do a SHIFT + click on the button “Restore”.

4 – Downgrade occurs at the end of 3 / 4 of loading, an error (1015), click “OK” and close itunes. itunes logo + USB port appear.

5 – Install libusb-win32 (libusb-win32-filter-bin-, then launch console iRecovery.exe. you find here

6 – Make a iRecovery.exe-s to fit in
the shell of the iphone

7 – Once in the shell, type their commands:

setenv auto-boot true


/ exit

8 – Reboot the iphone with the buttons HOME + SLEEP (10sec)

– Your iphone should have the iPhone 3GS firmware and you can follow our complete jailbreaking guide for  guide for iPhone 3.1.2 3Gs using blackran1. Yyou can then unlock y
our iPhone using ultrasn0w.

– For iRecovery.exe launches in console mode, start menu> run> cmd> then Desktop iRecovery.exe (eg if your file is on the desktop)

–  If you’re on Seven or vista, put in compatibility mode “Windows XP SP2, and run in administrator mode.

Download  libusb + iRecovery

Download iRecovery

Download the Original iPhone OS 3.1.3 firmware for iPhone 3GS.

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