As notified earlier, iPhone Dev-Team is expected to release PwnageTool and Redsn0w for iOS 4.3.1 untethered jailbreak within next few hours. As PwnageTool is only available for Mac OS X users, so Windows users must use Redsn0w to jailbreak iOS 4.3.1 on their iDevices. To use Redsn0w, you must be running stock iOS 4.3.1 firmware on your iPhone as a prerequisite. Upgrading to stock iOS 4.3.1 IPSW will also upgrade your iPhone baseband but with this guide, you can upgrade to stock iOS 4.3.1 while preserving your current baseband.
So the guide below is applicable to:
- Those iPhone users who do not own a Mac.
- Those iPhone users who rely on an unlocked iPhone.
- Those iPhone users who have unlockable (01.59.00, 04.26.08, 05.11.07, 05.12.01, 05.13.04, 05.16.01, 05.16.02, 06.15.00) baseband.
Steps to Upgrade to iOS 4.3.1 While Preserving Current iPhone Baseband:
- Download and install iTunes 10.2.1 from here
- Download stock iOS 4.3.1 IPSW for iPhone 4 or iPhone 3GS from here
- Download Sn0wbreeze 2.4b1 for Windows from here
- Launch Sn0wbreeze tool and click on Next button to get started.
- Click on Browse button and select stock iOS 4.3.1 IPSW which you downloaded in step 2.
- Now wait while Sn0wbreeze validates the IPSW you have provided. Once Sn0wbreeze has successfully validated the IPSW and identified your iDevice, click on Next button to continue.
- Choose Baseband Preservation Mode and click on the Next button. This option will not jailbreak your iPhone but will only upgrade the firmware while preserving current baseband.
- Now wait while Sn0wbreeze creates iOS 4.3.1 custom IPSW for your iPhone.
- Once done, use the instructions below to put your iPhone in DFU mode:
- Turn off your iPhone completely
- Press and hold the Home+Power button simultaneously for 10 seconds.
- After 10 seconds, release the Power button but keep holding the Home button until Sn0wbreeze detects your iPhone in DFU mode.