I'm right now on a 1st gen. IPhone (8GB) running on iOS 3.1.3 (well, it was still called iPhone OS ) tomorrow I'll be getting a new iPhone 4 (32GB), that will be running on iOS 4.1 I already downloaded the IPSW of 4.3.3 and redsn0w 0.9.6rc16 because as soon as I get it I want to update it to 4.3.3 and then I want to unlock it and jailbreak it.

In this guide you will learn how to jailbreak iOS 4.2.1iPhone 4, 3GS, 3G using RedSn0w on Windows. Just follow the step-by-step instruction to jailbreak iOS 4.2.1. See more jailbreak guides.

Important:

1. Unlock-Jailbreak Team Can now permanently factory IMEI unlock your iPhone 5S,5C,5,4S with jailbreak and get Cydia Installed on iOS 7.1 to iOS 7.1.1 untethered by white listing your IMEI in the.
2. Jun 04, 2012 These are instructions on how to jailbreak your iPhone 4S on the 5.1.1 firmware using RedSn0w for Windows. The Mac version of this tutorial is here. Please be aware that upgrading your iPhone to.

• Tether jailbreak: iPhone 4, iPhone 3GS (new bootrom), iPod touch 2G (MC Model), iPod touch 3G, iPod touch 4G. Tethered jailbreak for newer models, means if you reboot the device then to boot back into jailbreak state you need to connect your device with computer and boot it using RedSn0w.
• Untether Jailbreak: iPhone 3G, iPhone 3GS (old bootrom), iPod touch 2G (Non-MC)
  
• Unlock for iOS 4.2.1 is not available yet so keep away from jailbreak if you need to unlock your device as well.

Step-1

Download and restore iOS 4.2.1

• Download iOS 4.2.1 for your device.
• Download Redsn0w.

Step-2

Run iTunes and select your device from left pane.

Step-3

Hold down the Shift key from keyboard and hit the Restore button.

Select the iOS 4.2.1 firmware ipsw file that you have downloaded and hit the Open button. Let the iTunes finish the update process.

Jailbreak iOS 4.2.1

Iphone 4s Unlock Code

Step-4

Extract the downloaded redsn0w_win_0.9.6b4.zip file and run redsn0w.exe file.

Step-5

Hit the “Browse” button and select the iOS 4.2.1 firmware ipsw.

Step-6

When IPSW successfully identified, hit the “Next” button and let the redsn0w prepare jailbreak data.

Step-7

Iphone A1387 Unlock

Check the “Install Cydia” option and hit “Next”.

Step-8

Make sure your device is plugged into computer and Turned Off as well, hit the “Next” button.

Step-9

Now put your device into DFU mode, redsn0w will guide you to do that. Read the on screen steps to put your device into DFU mode.

Redsn0w will start jailbreak process, wait for the Done! message and then hit the Finish button.

When your iPhone finishes rebooting, now your iPhone is Jailbroken and you can find Cydia icon on springboard.

To reboot tethered jailbreak device, Check “Just boot tethered rignt now” option and hit Next button.

Thanks to Dev-Team 🙂

See also:

Unlock Iphone 4s

• Jailbreak iOS 4.2.1 Untethered with GreenPois0n RC5

Tutorials for iOS 6.0 – 6.1.2 untethered jailbreak

Iphone 4s Redsn0w Unlocked

Untethered jailbreak is available for all devices with iOS 6.0 – iOS 6.1.2. This includes:

• iPhone 3GS, iPhone 4, iPhone 4S, iPhone 5;
• iPod Touch 4G, iPod Touch 5G;
• iPad 2, iPad 3, iPad 4, iPad Mini;

If you don’t need cellular unlock use Evasion utility, tutorials are available here:

Unlock Iphone 4s Passcode

If you need custom firmware to preserve baseband modem version for iPhone unlock use SnowBreeze. Tutorials are here:

Network Unlock Iphone 4s Free