These are instructions on how to jailbreak your iPod Touch 3G and iPod Touch 4G using Greenpois0n for Windows. Greenpois0n supports iOS 4.1 and iOS 4.2.1.
These are instructions on how to jailbreak your iPod Touch 3G and iPod Touch 4G using Limera1n for Windows. Limera1n supports iOS 4.0, 4.0.1, 4.0.2, and 4.1.