How To Jailbreak iPad On iOS 4.2.1 Using Greenpois0n [Windows]

Chronic Dev Team

Chronic Dev Team just released greenpois0n to jailbreak iOS 4.2.1 for Windows for iPhone 4, iPhone 3GS, iPhone 3G, iPod Touch 4G,iPod Touch 3G and iPad.

In this guide, we will take you through the step by step procedure to jailbreak your iPad on iOS 4.2.1 using greenpois0n.

Here are some important points to note before you proceed:

  • Please note that jailbreaking your iPad may void its warranty and hence proceed with caution and at your own risk.
  • This guide is meant for iPad users only. iPhone 4 and iPhone 3GS users can checkout this step-by-step guide and iPod Touch 4G, iPod Touch 3G users can checkout this step-by-step guide.
  • Greenpois0n supports iOS 4.2.1 and iOS 4.1. So you need to first update your iPad with iOS 4.1 or iOS 4.2.1 to use greenpois0n.
  • Please note that this guide is only meant for Windows users. Mac users can checkout this guide.
  • Do not forget to backup your iPad before you proceed. You can refer to this post for instructions on how to backup your iPad.
  • Please ensure you are running latest version of iTunes, iTunes 10.1 or later.
  • After the jailbreaking process is complete, do not forget to checkout our article on tips to keep your iPad secure.

You can follow these step-by-step instructions to jailbreak your iPad:

  1. Go to and click on the Windows icon to download the latest version of greenpois0n. If the greenpois0n site is down then you can checkout this mirror site.
  2. Double click the greenpois0n zip file to extract the file and double click greenpois0n to launch the application.
  3. Next connect your iPad to the computer and power it off.
  4. Then click on the Prepare to Jailbreak (DFU) button.
  5. You will be prompted to put your iPad DFU mode. Greenpois0n will take you through the necessary steps.
  6. Press and hold the Sleep/Wake button for 2 seconds.
  7. Keep holding the Sleep/Wake button and also simultaneously also press and hold the Home button for 15 seconds.
  8. Then release the Sleep/Wake button but continue holding the Home button for 15 seconds.
  9. Once the iPad enters DFU mode, you should see Ready to Jailbreak, now click on the Jailbreak button.
  10. You should see greenpois0n jailbreaking your iPad.
  11. After jailbreaking is complete, you should see the Quit button, click Quit button to close the application. You should see text in verbose mode scrolling on your iPad’s screen.
  12. Your iPad will reboot. After it has rebooted, you’ll notice that there is a new Loader application on your iPad’s home screen.
  13. Tap on it to launch it. Select Cydia and then tap on Install Cydia button.
  14. After you have successfully installed Cydia, you can uninstall the Loader application as it is no longer required. Tap on the Options button and then Remove button to uninstall it.
  15. That’s it, your iPad is successfully jailbroken and you should see Cydia on the homescreen. Reboot your iPad and launch Cydia to install the latest updates.

If you’re new to the jailbreaking world and wondering what to do after jailbreaking your iPhone, checkout our jailbreak apps category page to find out the apps you can install on your iPhone using the Cydia app, which is the App Store for jailbreak apps.

Troubleshooting steps:

  • You can checkout our post with all the troubleshooting tips if you had problems jailbreaking your iPad.
  • If you don’t see Cydia in the Loader app after launching it then you can install Cydia using Redsn0w 0.9.6 RC8 (download link). You should just tick Cydia from the list of options and don’t use the Monte option.
  • Greenpois0n recommends a clean restore so if the above steps don’t work then you can try to restore your iPad if you desperately want a jailbreak as it is not ideal.
  • Connect your iPad directly to your computer (not via a USB hub).

As always, let us know how it goes and if you have a tip that helped you jailbreak your iPad using greenpois0n successfully then do share it in the comments section below.

[via iClarified]

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  • Cvega21

    Nice, slow but finally released none the less good job

  • BigDjo

    One of the first niggaz in the world to use this shit (I live in Algeria)! Worked like a charm on iPad!

  • Frank

    Worked like a charm 🙂 Thanks a lot to all that have made this possible!

  • tutuyutu

    The DFU process starts but during phase 3 (releasing sleep), the IPAD crashes…..
    I reinstalled already 3 times… and I’m not dumb !

    • I just jailbreak my ipad using 4.2

      it works just fine… just follow the steps or go to youtube for better details.

  • Drcav

    Worked perfect. A “Hello” from Belém-Pará-Brazil


    You should try again following the instructions but this time remove your head from your ass you twit.

  • Yaman

    Windows Version Released but not working its keep saying jailbeark failed:( retry………. any one

    using on iphone 3gs

    • Fady

      try with another PC

  • solorsyst3m

    I got mine working on Windows for my iphone4 woot! Thanks a million— YOU ROCK!

  • Yaman

    Windows Version Released but not working its keep saying jailbeark failed:( retry………. any one

    using on iphone 3gs
    Version : 4.2.1 (8C148a)
    Firmware: 05.15.04

    Feb 6 , 2011

    • Funny, it fails on my Mac running lion but works like a charm the first time on my windows box. go Figure?

  • JayRolla

    All about the Motorola Atrix. iPhone can kiss my ass good bye!

  • dave bockman

    Just tried it on my son’s iPod Touch, worked like a charm! Thanks devs!

  • Desparado

    Took just a couple of minutes and worked perfectly on my iPad. Will wait for my phones since I use the unlock.

  • Jk

    GrEen poison is the shiesta!!

  • Chronic dev team rules

    This is the best hack! works great and has no problems if you run it over redsnow tethered version. i am very proud of the Chronic team for developing suck a great hack its way better that redsnow and anyother hack out so far and comex and everyone else they are just wasting people’s time making us wait for 2 months for the untethered release. I am proud supporter of GreenPois0n

  • Neo

    Worked perfect on the latest ipad and ipod touch. Thanks a bunch guys

  • krisx

    Worked great thanks !!!

  • John

    ibooks not working on ipad after jailbreak. Any suggestions.

    • asa

      I am having the same issue. It will work for all but purchased books.

      Free books and PDF’s work.

      This is both my iphone 4g and ipad

      • Steve

        Same with me. iBooks not working for paid books on iPad and iPhone after JB with GP for 4.2.1

    • Alibah

      Same here. everything works perfect. I want to read my books ;(

  • becky

    is anyone having trouble jail breaking iphone 3g 4.2.1?? i keep having to retry….does this work for 3g?

  • Virtual

    I just finished jailbreaking it and it was very simple and easy and I even did it on top of my original tethered jailbreak.
    Thank you for this.

  • sobe

    Tried on 3GS new bootrom. Cydia very unstable. When out of cydia, no other actions using the activator shortcuts can be done. When phone went locked, cydia connections out. Cannot ssh using openssh.

  • ROB

    I had to disable my antivirus to open greenpois0n on windows 7,and then it worked great

  • Makara Kang

    I’m very love greenpois0n rc5 because it easy to jailbreak ipad and iphone 4

    all try to do work during jailbreak and easy to download cydia also


    makara kang

  • Ed

    Anyone get Error: POSIX Timed out when you open Cydia and it tries to download packages and releases? It goes through download packages and download releases.gpg and it seems like it get hung up after awhile and then I get that error! Is it still because Cydia servers are still experiencing heavy traffic or that Cydia is still working out the bugs on iOS 4.2.1? Please help! Let me know, Thanks, Ed

    • sobe

      Me same. U tried openssh?

  • Startek

    worked awesome for me…i got a couple of retrys but i just kept retyryig and it finished….yeah babyyyy

    • mario

      how many retries cause my thing isnt working it just puts my ipad in the itunes usb screen

  • vaibhav

    does it work on iphone 4 also????with ios 4.2.1 firmware

    • bogs

      it’s intended for that..

  • Ralph

    WOrks fine.. Thanks Chronic Dev Team

  • Jayson

    Wait… I thought iPad was on iOS 3!

  • silverhazzard

    i have ipad wifi+3G already jailbroken from 3.2 version. if im going to update it to 4.2.1 does my software unlock with ultrasnow will lost? and does the baseband will change also? do help pls, thanks 🙂

  • richard

    worked great first time over the top of redsnow. Didnt even delete Cydia from the redsnow break. Now boots untethered every time.
    if you have problems try using redsnow tethered jailbreak first then run this over the top.
    ipad wifi 4.2.1
    redsnow tethered jailbreak

    thank you!!!

  • oleg

    cool worked perfect, thank you guys very much. Greenpoison is the best!!!!!!!!!!!

    • mo

      Ran multiple times. No jailbreak. 4.2.1 ipad 8C148

  • TIM

    Windows Version isnt working for me its keep saying jailbeark failed, retry
    using on iphone 3g
    Version : 4.2.1 (8C148)
    Firmware: 05.15.04

    PLEASE HELP!!!!!

  • James

    Easy, thanks so much, ipad now rocking 4.2.1, also jailbroke my mates iphone 4 without any problems

  • robson

    it works!!! no problems.
    from Americana/sp – Brazil

  • cordovanian

    Worked fine on iphone 4 but unable to Jailbreak iPad with 4.2.1 using windows 7 64bit

  • Justin

    This is a dumb question but i have an iPad 3g on 4.2.1 and bb 7.10.00 if i jailbreak my iPad will the sim work or do i have to unlock it with ultrasnow.

  • Worked a treat for me!

  • TIM

    What am i doing wrong?? i can’t get to dfu mode,i tells me to retry, i have followed step by step all 26 times still no luck,please help!!!!

    • Stephanie

      hey tim, i´ve got the same problem with the same iphone 3g, 4.2.1, 8C148, Firmware 05.15.04.

      Have you been able to jailbreak?? thanks if you know any solution!

  • Dhruv Srivastava

    I jailbroke my ipod touch and my moms Ipad running on 4.2.1 successfully. However, after I installed cydia, I tried to upload hackulos as a source on both my ipod and ipad. On my Ipad it worked perfectly, I managed to install installous. On the Ipad though, cydia crashes everytime i try to add the source.

    Please help.

  • bogs

    jb was easy… so far, only issue is that ibooks won’t work with purchased books.. only the pdf’s are accessible..

  • mpfiz

    seems like greenpois0n does not work for iPhone 3G. it is not listed as a device in the readme file.

  • Caveoboy

    Any ideas when the ibook issue will be fixed?

  • Don Quishock

    I tried the windows version for my ipad 3 times, says its ok but no loader appears ?

  • Don Quijote

    i use green poison to jailbrake my iphone 3gs new bootroom with ipad baseband and works great the only thing is when i try to watch a youtube video in any web page it crash dont know why but in the youtube app runs good ! Any help!!!

  • Brian

    Working on iphone4 but not on iPad. When I try it on my ipad I get Jailbreak Failed and ipad just boots normally. Using windows xp, itunes Any ideas?

  • Travis

    If you are running windows 7 64 bit, right click greenpois0n application and run as administrator

  • jchen187

    Well done. Jailbroken my iPad successfully, Cydia and Installous installed successfully 🙂 Thank You !!!

  • Julab

    Is there any change in battery life (in particular the iphone 3gs) after its jailbroken? Have a tethered 3gs, and the battery is decent, but could be better.


  • George

    Jailbroken my iPad(wifi) successfully, Cydia and Installous installed, but GPS does not work. Any idea why ?

  • raj

    jaibreak was successful but loader does not work… how do i fix this….

    • Manz

      Same problem.. Please do reply

  • Drake

    I just bought ipad with firmware 4.2.1 baseband 7.10.0 and I’ve tried several times on windows 7 32bit and it fails each time.

    I even used it in Windows XP (Service pack 2) compatibility mode, run as administrator and it does the same thing…”jailbreak failed”.

    I’m presently downloading the firmware so I can use redsn0w (tethered). If that works, then I’ll try using Greenpois0n again to see how it goes.

    If all works well, I’ll update y’all.

  • Drake

    Like promised. I have an update… If you were receiving jailbreak failed errors or something like this unable to find gBdevList

    unable to find fs_mount
    unable to find fs_unmount
    unable to find fs_load_file
    Greenpois0n initialized

    then you need to follow the instructions below because I just used it and I’ve been able to jailbreak the ipad with firmware 4.2.1 successfully.

    What I did was,

    1. Jailbreak the ipad using redsn0w 0.9.6b (you can download that here

    2. Follow instructions on this page ( to jailbreak.

    3. once successful using redsn0w (tethered), you then follow the instructions on this page above to jailbreak with Greenpois0n and you’ll have an untethered jailbreak of the ipad 4.2.1

    I hope this helps someone else.

    I need to go download some apps.:)

  • joeyrn

    worked for me… thanks a lot guys…

  • iPad new user

    YEAH! success, my 1st time jailbreak on my iPad. Very Happy. Dont know it work on iPhone. Will try.
    Thanks Greenpois0n.

  • mhd taj

    plzz someboddy help
    every time i jailbreak they says jailbreak completed then when i open itunes an error occured so i have to restore the ipad its ios 4.2.1 and this green poison
    plzz help

  • mechanics

    wow… it works thanks

  • tovolini

    extremely easy to follow. thanks!

  • Reeve

    i get successfully jailbreak..but i want ask now my ipad can turn off every time or reboot ,andthen no jam …

  • Reeve

    my battery always show 100% after jailbreak

  • Filipe

    Worked perfect =D . A “hello” from Brazi-Ceará-Fortaleza 27/03/2011

  • bma

    its works well many thanks.

  • Loli

    Hey 🙂 I think it worked but I’m still not able to download from can anyone help me out? Thanks a bunch 🙂
    P.S.: I’m using an iPad

  • JM

    I just finish jailbreaking my Ipad but the Loader App is not working.. What should I do?

  • Ayaz Khan

    IT WORKS FOR 4.2.1


  • i was so frigen exicted to see my ipad reboot after jailbreakin it. i saw the loader app and clicked on it as fast as i could when an uncomfortable messeage popped up in front of my wide eyes:”Please make sure that you’re connected to the internet before launching Loader.” WHYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY?!?!?!?!?!?!?!?!?

  • Dev

    Great! It worked. Big Thanks to you guys.

    Keep up the good work. Gonna jailbreak my iPhone 4 as well.!

  • Die

    How can I downgrade os 5 to be os 4.2.1? I already tried some method like tiny umbrella, edit Hosts file on etc, but it didnt work.

  • jesuslive 98

    does enyone have this messege reapeting failed to get appes5l8920xarm7m. please tell tell me what i did wrong

  • Sidakid

    Awesome. Hats off to you guys. It took a few attempts but got it done. Two things to remember. If your Ipad refuses to turn on after one of the failed attempts,
    1. Press sleep + home for 10 seconds.

    The second point is that don’t forget to hold the “Home” button for a good 20 seconds instead of the 15 in Step 3.

    You’re all set!

  • kojaq

    U guys ruuuuuuuuuuule, just jailbroke my ipad in 5 min, sweeeet.
    thank u hacker R us…

  • thanks alot 🙂 , it’s worked for my ipad

  • shane

    this didnt even work for me, i went to greenpois0n and i downloaded the stupid thing and now i dont know what to do

  • Elizabeth Paniagua

    iPhone 3G, 4.2.1 (8C148), 05.15.04 — Jailbreak/Unlock? okay i have tried the greenpoison and redsnow without luck when i open redsnow it does not show any files when i hit browse, and the greenpoison just keeps saying try again, i am very new to Iphones and am really not sure what to do, but i cannot get past the pressing the button for 15 seconds i just get the message to try again, any suggestions, help please.