iPhone Dev Team has finally released Redsnow 0.9.6b2 with many new features for both Windows and Mac users. The new version of Redsnow uses the Geohots’s limera1n exploit to jailbreak all idevices (iPhone 4, iPhone 3GS, 3G, iPod Touch 4G/3G/2G Non MC models only and iPad) on latest public iOS version.
The new features in Redsn0w 0.9.6 B2 are pwned DFU mode that allows users to restore the iPhone to custom cooked firmware on Windows, custom bootlogos for iPhone 3GS owners with old bootrom and tethered boot.
The last feature, teathered boot, is for future use only and currently it has no use in this version. The instructions to jailbreak iOS 4.1 with Redsnow 0.9.6B2 are same as mentioned in these posts (1) and (2).
If you rely on unlock and don’t have access to Mac, it is highly recommended that never use this jailbreak because it won’t preserve the baseband and there is no unlock available for iOS 4.1. In case you want to enjoy the new features of iOS 4.1 version, get a custom cooked firmware with PwnageTool to update your iPhone while selecting the Pwned DFU mode in Redsn0w 0.9.6B2.