As promised, Chronic Dev Team has just released Greenpois0n iOS 4.2.1 untethered jailbreak for Windows for iPhone 4G, 3GS, iPod touch 4G, 3G, 2G and iPad.
You can follow our Mac guide, it’s the same exactly, check the full step by step guide.
Download GreenPois0n for Windows
Download iOS 4.2.1 for iPhone 4, 3GS, iPod touch 4G, 3G, 2G and iPad