How To: Jailbreak iOS 4.2.1 (Untethered) [Mac]

What Devices This Works On

• iPhone 3GS, 4
• iPod touch 2G, 3G, 4G
• iPad

What You Need

• A Mac running OSX 10.5+
• iTunes 10.1+
• GreenPois0n RC5b3 (click here)

Steps 1) Back-up your iDevice in iTunes. This is done simply by syncing it. 2) Turn off your device, but keep it plugged in. 3) Launch GreenPois0n. Click the button that says "Jailbreak" and follow the on-screen instructions. 4) Once your device finishes and boots up, launch the new application called "Loader." 5) Install Cydia 6) There you go! Your device is now jailbroken on 4.2.1! Common Errors a) "My device doesn't load the jailbreak and just sits there with a few lines of text on it!" -Restart your device (by holding the Power and Home buttons simultaneously) and try again. This jailbreak has a few bugs, so you may have to try a few times. I personally had to try four times for one device and seven for another. But hey, it's worth it. b) "Nothing loads in the Loader application! How do I get Cydia now?" -This is because the GreenPois0n website is overload. You can do one of two things. You can wait, or you can use the workaround. The workaround is quite simple. First, download Redsn0w 0.9.7b6 (click here) and the appropriate 4.2.1 firmware file for your device (click here). Launch Redsn0w, go through the process, and select install Cydia. Also, make sure "Jailbreak Monte" is deselected if it is an option. It will jailbreak your device (even though it is already jailbroken) and install Cydia. Normally, when you jailbreak 4.2.1 with Redsn0w, it would be tethered, but because you jailbroke it with GreenPois0n, it will be untethered.

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