Few days ago We have released Greenpois0n RC5 untethered 4.2.1 jailbreak on all idevices. Now here is good news for Windows users finally We released Greenpois0n RC5 for Windows here.
Greenpois0n RC5 B2 for Windows is released and enable you to untethered jailbreak ios 4.2.1 and supports following devices

We present afull guide for jailbreaking ipad using greenpois0n RC5 jailbreak follow steps below and enjoy with jailbreak.

Just mere hours after the first Verizon iPhone’s began arriving the software the units are shipped with, iOS 4.2.6, reportedly designed specifically for the CDMA-compatible unit, has in fact been jailbroken.

Enjoy with Greenpoison jailbreak forwindows and mac. you can find greenpois0n jailbreak links below.

We have released GreenPois0n RC5 just yesterday for Mac OS X and they are about to release the Windows version. Most of our readers has successfully jailbroken their devices but few of them are still facing some problems. So here's a quick instructions to beyond this issues & bugs.

A few hours ago, We released Greenpois0n RC5 which allows us to apply an untethered jailbreak to our iOS devices running iOS 4.2.1 ( and iOS 4.1.1 ). The software was pretty buggy, so a couple of hours later they released a new update, RC5_2, which should fix all the issues but there’s one thing missing: the custom animated bootlogo. In this tutorial we’re going to show you how to enabled it.

We have just confirmed that the upcoming Greenpoi0sn RC5, which will bring untethered jailbreak for iOS 4.2.1, will support animated boot logo on all iOS devices.

Greenpois0n RC5 jailbreak for windows will be available here on greenpois0n.us very soon follow us on our facebook and twitter below to get all news about greenpoison.

Now you can update your iPhone 4 to iOS 4.2.1 with preserving 1.59.00 baseband, which means that you will be able to unlock your iPhone 4 with ultrasn0w 1.2. Let's check out the full step by step guide after the jump