Windows users can jailbreak their iOS device on iOS 4.3.1 with Sn0wbreeze 2.5.1 by iH8Sn0w. This version of Sn0wbreeze allows you to jailbreak iPhone 4, iPhone 3GS, iPad, iPod Touch 4G, iPod Touch 3G and Apple TV 2G.
Unlockers - Stay clear of this process. Ultrasn0w 1.2 needs to be fixed to for iOS 4.3.1