Few days back Redsn0w 0.9.8b1 was released for MAC by Dev-Team, Now they have released the same Beta version for windows. The Jailbreak is Tethered, means every time you Reboot your phone you will need to use Redsn0w’s Just Boot Tethered now option.

The Firmware iOS 5b1 is available for Download and Download it only if you are developer because iOS 5b1 is also in its Beta stages and not released for General Public. So avoid iOS 5b1 for now.

You can Download Redsn0w 0.9.8b1 for Windows from here and follow the guide present here.