Members of Chronic Dev Team has just released a new version of greenpois0n which brings support for Apple TV 2G. Greenpois0n RC6 now available for both Windows & Mac machines that untethers Apple TV 2G jailbreak on iOS 4.2.1.
HERE and you'll get Apple TV 2G untethered jailbroken on iOS 4.2.1. Download links of greenpois0n RC6 below:
Download Greenpois0n RC6 for Mac OS X from HERE.
Download Greenpois0n RC6 for Windows from HERE.
Download iOS 4.2.1 for Apple TV 2G from HERE.
link : REDSNOW