Downgrade From Firmware 4.0 to Firmware 3.1.3 on iPhone 3G [GUIDE For WINDOWS Users]

Many users have found it difficult to downgrade the iPhone 3G on Windows operating system, particularly with Windows 7. This guide explains how to do this without problems. To downgrade the iPhone there are two ways parellel. First one is where the end of the installation of firmware programs are used as iRecovery or Easyirecovery but are not very compatible with Windows, especially on Windows 7, and another described by Italian site, very simple and consists of having simply use the of working in DFU mode (redsn0w) and then exit the recovery mode without having to install usbLib or similar.

Guide Steps:

1. Download firmware 3.1.2 and 3.1.3 (if you’re interested otherwise just downgrade to 3.1.3 and 3.1.2).

2. Download redsn0w 0.9.4.

3. Download Spirit.

4. Install the firmware (3.1.2 or 3.1.3) via iTunes by clicking and holding the reset button to find the shift. Ipsw file on your computer. Error 1015 will apear reply OK and close iTunes.

5. Open redsn0w (with WinXP compatibility mode and as administrator) when iTunes is closed. Be careful not to open redsn0w while iTunes has not yet finished, otherwise generating an error and iTunes closes without completing the installation of the firmware.

6. Click the Browse button and run the patching of redsn0w Firmware 3.1.2 even if you have 3.1.3 installed on the device. Follow the steps of redsn0w and when it asks to install Cydia don’t select it. Cydia installed with redsn0w on this occasion, an error generates and does not run the Apple device. Once finished the jailbreak with redsn0w you will be come out from recovery mode.

7. Whether you have installed the 3.1.2 and 3.1.3 jailbroken Spirit carried the device. Obviously jailbreak had already happened but working with Spirit we install Cydia..

8. For iPhone users with a stranger and locked the phone, no problem of course! Thanks to Cydia repo ultrasn0w preinstalled on the iPhone is released in an instant.

9. Obviously you cannot install 4.0 on the backup device downgraded but you can use programs such as iPhone Backup Extractor.