How To Jailbreak iOS 4.2.1 iPhone 4 3GS With Greenpois0n RC5 Windows


by casey on February 6, 2011

Greenpois0n RC5 for Windows is already released. The Greenpois0n RC5 for Windows can jailbreak iPhone 4, iPhone 3GS, iPod touch 4G, iPod touch3G and iPad. Follow the HOW TO GUIDE to do a clean and safe untethered iOS 4.2.1 jailbreak using Greenpois0n on Windows operating system.


STEP 1: Download the Greenpois0n RC5 for Windows.

STEP 2: Extract or Unzip the downloaded file

STEP 3: Launch the Greenpois0n.exe app by clicking it.

STEP 4: You MUST Switch Off your iPhone 4 or iPhone 3GS device before you connect it to your PC.

STEP 5: Click the big button which says “‘Prepare to Jailbreak (DFU)”

Greenpois0n rc5 Windows

STEP 6: It will prompt you instructions to put your iPhone 4 / 3GS Touch into DFU mode. It will prompt you to press and keep on holding the Sleep for 2 seconds.

Greenpois0n rc5 Windows 1

Keep on holding the Sleep and press and hold the home for almost 10 seconds.

Greenpois0n rc5 Windows 2

Now Release the Sleep Button and keep on holding the Home for almost 15 seconds.

Greenpois0n rc5 Windows 3

STEP 7: Now your device is in the DFU mode. Click on the big Jailbreak Button.

Greenpois0n rc5 Windows 5

STEP 8: Greenpois0n tool will do the rest of the jailbreak process.

Greenpois0n rc5 Windows 6

STEP 9: Click on the Quit once the process is completed.

Greenpois0n rc5 Windows 7

STEP 10: Your iPhone 4/3GS device will now restart. A Loader will now appear on your Springboard after the Restart. Click to launch the Loader.

STEP 11: Select Cydia and press the big Install Cydia button.

STEP 12: It will now Install Cydia. After that it will prompt you if you want to remove the Loader from your iPhone 4/3GS Touch device. Click on the Remove button and then press Home. Your iPhone 4/3GS Touch will now Restart.

Congratulations! You have successfully jailbroken iOS 4.2.1 running on iPhone 4/3GS Touch 3G/ 4G using Greenpois0n for Windows OS.

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  • Sean Oxby

    You say you must have phone switched off before connecting to computer. I have done 2 iPhone 4′s one 32 gig and one 16 gig both of which I put into DFU mode from step 6 and both jailbroke fine. Just thought I’d update you on thisnnTankie_Sean n

    • Steven Barnier

      I have done the jailbreak and cydia won’t install the sinfuliphone repo it can’t find the URL what do I do now as it won’t accept my copied apps

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