The Window version of the “Absinthe” GreenpoisOn jailbreak tool is out now. Those with only windows-based computers can now jailbreak their A-5 powered iDevices, iPhone 4s, iPad 2 and iOS 5.
It might not be easy for you to download it from the GreenpoisOn website, but you can download it from here to the windows version of the Absinthetool.
Before running the actual jailbreak app, it would be good to get some tips on how to use it well. And for easy reference purpose, you can also download the Mac OS X version of the tool.