Sn0wbreeze 2.3b1 is now available for Windows users to jailbreak iOS 4.3 running on iPhone 4, 3GS, iPad and iPod touch. Just like PwnageTool for Mac, Sn0wbreeze jailbreak is also tethered for all devices, which means you will have to boot into a jailbroken state every time you reboot your device.
rubyra1n.blogspot.com/2011/03/jailbreak-ios-43-on-iphone-4-3gs-ipad.html#