Now there is no official way to downgrade to OS 3.1.3 from iOS4, but there is always an unofficial way. Here are the steps to downgrade from iOS4 to OS 3.1.3 –:
1) First navigate to “c:\windows\system32\drivers\etc\” and open the ‘hosts’ file in notepad. To do so, right click on the file and select Open With->Notepad. At the end of the document, add this string
2) Now connect your iPhone to iTunes in recovery mode. To do so, first switch off your device. Then press the Home button on your handset and connect the USB cable. As soon as you connect the USB cable, the device will boot up and a “Connect To iTunes” screen will be displayed. Users can now stop pressing the Home button.
3) Fire up iTunes now. You will see your iPhone/iPod Touch detected in recovery mode. Now, whilst pressing the Shift key for Windows users or Alt key on the Mac platform, click on the Restore option.
Now just select the original OS 3.1.3 and voila, you are done.
Yeah you may need to do the notepad thing first, I aint sure, as mine is already set to those settings. You can definately restore or downgrade using the SHSH files, as I did it at the weekend from 4.0.1 to 3.1.3.
do everything u did as off before but change the host file first by adding
remember to run as admin when changing the host file.
so it should look something like this after editing it.
# Copyright (c) 1993-1999 Microsoft Corp.
# This is a sample HOSTS file used by Microsoft TCP/IP for Windows.
# This file contains the mappings of IP addresses to host names. Each
# entry should be kept on an individual line. The IP address should
# be placed in the first column followed by the corresponding host name.
# The IP address and the host name should be separated by at least one
# Additionally, comments (such as these) may be inserted on individual
# lines or following the machine name denoted by a '#' symbol.
# For example:
# 184.108.40.206 rhino.acme.com # source server
# 220.127.116.11 x.acme.com # x client host