Chronic Dev Team have recently released Greenpois0n (untethered) for Windows that jailbreaks the iOS 4.1 firmware. Below is a simple step by step guide on how to jailbreak iPhone 4, iPhone 3GS, iPod Touch 4G
and iPod Touch 3G on iOS 4.1 and iOS 3.2.2 for iPad using Greenpois0n ( download link at the end ).

Greenpois0n supports the following iDevices:

* iPhone 4
* iPhone 3GS
* iPod Touch 4G
* iPod Touch 3G
* iPad

Check out the tutorial after the jump.

Jailbreak iOS 4.1 Using Greenpois0n [How To] :

1) Download Greenpois0n ( link below ).

2) Once the download is complete, move gp_win_rc2.zip on your desktop and unzip it.

3) Open folder and launch Greenpois0n.exe.

4) Click on the button ‘Prepare to Jailbreak (DFU)’.


 5) Greenpois0n will display the instructions to put your iDevice in DFU Mode.

For DFU Mode : Press the Power button for two seconds, press Home + Power for 10 seconds, release the Power button and keep pressing the Home button.


6) Your iDevice will now be in DFU mode and then ready for jailbreak.

7) Now, Greenpois0n will prepare to jailbreak your iDevice. Once the process is complete, Quit button will appear on Greenpois0n window.

 

8) After your iDevice restarts you will notice a new Loader application on your Springboard. Press to launch it.


9) Press to select Cydia then press the Install Cydia button that appears.



10) Once Cydia has installed successfully you will be asked if you want to remove Loader from your device. Press the Remove button then press the Home button. Your device will now automatically reboot. When your iDevice has restarted, you can run Cydia.


Now, you have successfully jailbroken your iDevice on iOS 4.1

Note : If Greenpois0n doesn’t work for you, you can use Limerain (tutorial here).

Download :  Greenpois0n  ( Direct Download )

Note : There is a Mac button on the Greenpois0n website, but it’s not functional.

As always, please don’t forget to tell us how it goes. Feel free to ask any kind of queries and issues in the comments section below.

Update 1 :

Latest version of iTunes is required.

Update 2 : 

New RC3 version released for Linux (download) and Windows (download). 

Update 3 (10/17/2010) :


New RC3 version released for Mac (download).

Stay tuned to Mod Your Pod  for the latest updates and news on Greenpois0n.