How to Jailbreak iOS 4.2.1 with Greenpois0n RC5 b2 for Windows

Feb 6, 2011 by

With the release of Greenpois0n, I decided to use my own iPod as an example of how to jailbreak iOS 4.2.1 with Windows. Make sure you backup your files and apps and packages prior to doing this.

  1. Update your device via iTunes.
  2. Wait as your device is updated via iTunes.
  3. Now, I have always had difficulties and problems with updating and/or restoring using iTunes. So we’re going to have to wait. I always end up panicked because my iPod has been screwed up numerous times, so I have a right to be worried when it takes a while to wait for iPod. (Upgrading to iOS 4.1 resulted in a restore mode restore, upgrading to iOS 4.0 was caused when I screwed up my iPod completely and happened to restore it an hour before.
  4. for iTunes to update and verify the software.
  5. Continue to wait as iTunes does its inefficient and stupid tasks. And then continue to wait as it restarts.
  6. It’ll show that bar thing. I’ve always hated those because this one time, a Cydia package got rid of my system version file. It would half load that bar thing and it would get stuck. I narrowly avoided that and somehow managed to SSH into there and make my own system version file.
  7. Now at this point, you have a completely clean, legitimate device. Sans the battery percent, which was left there. At this point, take some time to check out your new iOS 4.2.1 device.
  8. Open Greenpois0n.

  10. Power off your device, as the program states.
  11. Press Prepare to Jailbreak (DFU).
  12. Follow the DFU mode steps.
  13. Press Jailbreak!
  14. Wait as it flashes a white screen then runs command line commands.
  15. Cream in your pants when you see that animated boot logo.
  16. My luck has run out as apparently I’m still seeing the boot logo after a couple minutes. pod2g has said that it may take a while. Though a couple seconds prior to his saying that, I did a soft reset thinking he was not going to reply. Hint: if you see a boot logo, wait for it. I screwed up. Wish me luck.

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  • Benjamin

    My iPod 3G did the same thing. Second time around I held the Home button until the Verbose boot started. That seemed to help, as it worked perfectly. Hope it works for you too!

  • So if I’m already jailbroken on 4.1 I can update normally and use GP? Hope so….

    • Benjamin

      I had to do an update to factory before GP would work. Just make sure you back it up first, so you can restore it after the JB is complete

      • Ok, thanks

        • Worked for me. Just had to run Greenpois0n three times.

          • I had to run it two times :)

  • I really hate those animated boot logos…

    They don’t even work that well…

    I’ve had my boot logo as the pwnapple for years already.