Tag Archives: Downgrade iPhone-OS

How to downgrade iphone ios firmware 4.00 to Version 3.1.3


Not many days ago  Apple released iOS4 which is compatible with the iPod3G, iPod Touch , iPod Touch 2G, iPhone 3G and  iPhone.Many users updated their iPhone to OS deliberately or inadvertently and now discovering methods to downgrade back to earlier iPhone firmware. If, you upgraded it to iOS 4.0 and now you want to go back to previous 3.1.3, you may chase the steps scheduled underneath.
Remember ECID SHSH certificate for firmware 3.1.3 is required to downgrade the firmware on iPhone 3G and iPod touch.

Downgrade iPhone-OS-4.0 to 3.1.3
Following are the steps to  Downgrade iOS 4.0 to 3.1.3 OS Firmware:

Step #1:
First we have to create a manual change to the hosts file with respect to the Windows operating system.
Just went to the following path “c:windowssystem32driversetc . After that open the hosts file in a notepad or wordpad.
For MAC users they can steer to the path “/etc/” and they can open the hosts file with TextEdit.

Step # 2:
Add “ gs.apple.com” at the end.  It’s helpful to forward requests for certificates for validity that iTunes will make to the Saurik server.

Step #3:
Set recovery mode in your device.
Now turn off and unplug your device from computer.
Now push and hold the Home button while reconnecting the USB cable to your iPhone. Note that once iPhone is connected it must power on the device.
Carry on holding the Home button until you see the iTunes logo appears and then finally Connect to iTunes will be shown. Now you are ready to release the Home button.
Now that the logo is appeared in iTunes, release the Home button and make a normal recovery.

Step #4:
Windows Users:  Open ITunes and perform a normal reset through holding down the SHIFT key and click restore in iTunes.

Mac Users: Open ITunes and perform a normal reset through holding down the ALT key and click restore in iTunes.

Step # 5:
Choose the original 3.1.3 firmware and wait for the completion of the process.
Enjoy you have Downgraded iOS 4.0 to 3.1.3 Operating system Firmware