How to: Jailbreak Untethered iOS 4.2.1 using Greenpois0n.[WIN]

Members of Chronic Dev Team has finally announced the release of the long awaited GreenPois0n RC5 for Windows. This tool brings untethered iOS 4.2.1 jailbreak for all iOS devices. Keep in mind, the software is only available for Mac OS X & Windows. A Linux version will be coming very soon.


Follow the below guide for step by step instructions to convert your tethered jailbreak to untethered jailbreak on iOS 4.2.1:


STEP 1: Your device must be on iOS 4.2.1, then download GreenPois0n RC5 for Mac OS X from here. [Mirror]

STEP 2: Launch GreenPois0n RC5 then connect your iPhone into your Mac via USB and click on Jailbreak as shown below:

STEP 3: Follow the instructions shown on the screen to enter DFU mode:

STEP 4: Once jailbroken, you'll get Cydia installed on your iOS device and you won't need to use Just tethered boot right now option anymore.

That's all.. Enjoy your untethered iOS 4.2.1! Cheers.

[How to] Unlock iPhone 4 on iOS 4.2.1 / 1.59.00 Baseband after Jailbreak with Greenpois0n RC5

Now you can update your iPhone 4 to iOS 4.2.1 with preserving 1.59.00 baseband, which means that you will be able to unlock your iPhone 4 with ultrasn0w 1.2. Let's check out the full step by step guide after the jump

STEP 1: Download TinyUmbrella from here.

STEP 2: Open TinyUmbrella then click on "Start TSS Server"

STEP 3: Open iTunes.

STEP 4: Now, Click on "Restore" NOT "Update"

STEP 5: Now you will get "Error 1013" which means that your baseband has been preserved.

STEP 6: Exit iTunes.

STEP 7: Now you have to jailbreak your iPhone 4 with the Greenpois0n RC5, follow our guide posted here.

STEP 8: Finally you can unlock your iPhone 4 running baseband 1.59.00 using Ultrasn0w 1.2.

Note: this guide is only work with iPhone 4.

How to: Jailbreak Untethered iOS 4.2.1 using Greenpois0n.[OSX]

Members of Chronic Dev Team has finally announced the release of the long awaited GreenPois0n RC5. This tool brings untethered iOS 4.2.1 jailbreak for all iOS devices. Besides you do not need to have '4.2b3' SHSH blobs saved in Cydia, unlike the Redsn0w 0.9.7. Keep in mind, the software is only available for Mac OS X. A Windows version will be coming very soon.


Follow the below guide for step by step instructions to convert your tethered jailbreak to untethered jailbreak on iOS 4.2.1:

STEP 1: Your device must be on iOS 4.2.1, then download GreenPois0n RC5 for Mac OS X from here. [Mirror 1, Mirror 2]

STEP 2: Launch GreenPois0n RC5 then connect your iPhone into your Mac via USB and click on Jailbreak as shown below:

STEP 3: Follow the instructions shown on the screen to enter DFU mode:

STEP 4: Once jailbroken, you'll get Cydia installed on your iOS device and you won't need to use Just tethered boot right now option anymore.

That's all.. Enjoy your untethered iOS 4.2.1! Cheers.

How to Put an iPhone Into DFU Mode

DFU means Device Firmware Update. If a restore using Recovery Mode doesn't work you will want to use DFU Mode as a last resort. When placing your iPhone into DFU Mode it does not load the OS before attempting the restore


Watch the Video!
For your convenience this tutorial is available in video format also. Click the Watch It button to view the tutorial!

To put the iPhone into DFU mode so you can do an iTunes firmware restore follow these steps:
Step One
Open iTunes and connect the iPhone to your Mac.

Step Two
Press and hold the Home button and the Sleep/Wake button at the same time.

Step Three
After exactly 10 seconds release the Sleep/Wake button. Continue holding the home button until you iTunes pops up a message telling you that it has detected an iPhone in recovery mode.

The iPhone screen will remain black like this:

NOTE***: It may take a few attempts to get your iPhone into DFU mode. Generally, I hold down both buttons then release the Home button just before I think the Apple logo would appear. If you are still holding both buttons down and you see the Apple logo you are holding them down for too long!