The "untethered" green poison jailbreak for iOS 4.2.1 is finally here, with some of the errors fixed and good to go for both Windows and Mac. This is great news especially for iPhone 4 and iPad users who have been waiting for just such a thing so they can customize their gadgets. The green poison jailbreak also works for iPhone 3GS and Apple TV 2G on iOS 4.2.1.The green poison jailbreak is not unlocking software
But first, to clear misconceptions that some newbies may be laboring under, jailbreaking is not the same as unlocking. Even using the untethered green poison jailbreak will not unlock a locked phone. If are intent on lifting the carrier restrictions of your gadget, you'll need to get unlocking software or have a professional do it for you. In general, you do need to use the green poison jailbreak or similar first before you have your gadget unlocked, but not vice versa. However, for the iPhone4, you cannot upgrade to 4.2.1 iOS yet if you want to unlock your phone. This will upgrade the baseband and as of this writing, there no unlock for that yet. It sucks, I know, but if you don't care about unlocking your iPhone at all, then the green poison jailbreak is your ticket to third party apps heaven.How to use the green poison jailbreak
The green poison jailbreak is a work in progress, so for those who are faint of heart, please note that you may encounter some bugs that need to be fixed. In this version, which is the GreenPois0n RC5 2, some errors that have been reported, particularly the initialization error has been fixed.
But there are still mixed reviews on the performance of the green poison jailbreak , so you will need to take a leap of faith if you can't wait for the "improved" versions that will surely come. If you're not sure, check out alternatives in BestJailbreakSoftware. As always, when something bad happens, you can always restore via iTunes.
Now, for those brave enough to proceed, this is how to do the green poison jailbreak:Make a back up of your data and then set it up as a new device in iTunes, using the iOS 4.2.1 version. Jack in your gadget to your computer using the USB, and turn the gadget off. Download the green poison jailbreak . For Windows users, download the green poison jailbreak here. For Mac users, here's the link. Run the green poison jailbreak and click "Jailbreak" Follow the instructions that will flash on your screen carefully, including the sequence and how long to hold down the specific buttons. Depress the sleep button for 2 seconds before depressing the home button. Keep this position for 10 seconds Let go of the sleep button only, still holding down home You should be in DFU mode by now, and click on "Jailbreak" to start the actual green poison jailbreak process. Let the green poison jailbreak install, and afterward your iPhone or iPad should display a loader icon, which once launched will let you install Cydia. If you're jailbreaking an Apple TV, you'll need to use SSH or Terminal to access the software.
Well, that's it. Good luck and hope you have no problems using the green poison jailbreak!