RedSn0w 0.9.6 b1 for Mac OS X was released a while ago. Today DevTeam created a version for Windows users. RedSn0w 0.9.6 b1 can jailbreak iOS 4.1 and iOS 4.1 running on iPhone 3G or iPod touch 2G.
Select your stock 4.1 or 4.0 ipsw (you’ve already used this to update your device to 4.1 or 4.0)
Select “Install Cydia” and any of the other options shown above, then click “Next”. Use DFU mode to install the jailbreak.
This is still beta, so there might be some problems:
Any Windows users seeing “Waiting for reboot” for too long (more than 20 seconds or so), please try “shaking” the JB process by unplugging then replugging your USB cable (while letting redsn0w continue to run). Also, try using a USB port “closer” to your computer (as opposed to on your monitor or behind another hub).
As usual DevTeam reminds us: IF YOU USE THE ULTRASN0W UNLOCK, PLEASE WAIT FOR PWNAGETOOL TO SUPPORT 4.1. DO NOT USE REDSN0W
That’s because to use redsn0w at 4.1, you need to already have updated to official 4.1 from Apple. If you do that, you lose the ultrasn0w unlock (possibly forever).
Apple released iTunes 8.2. You can download it here.
This update breaks your ability to use QuickPwn, PwnageTool, and iPhone Tunneling Suite (ssh over usb). Many file managers do not work with iTunes 8.2 installed. We don’t think this is a deliberate breakage of these tools. It’s just that Apple has updated a low-level USB protocol. It may also break Palm Pre’s connection to the device.
So if you jailbreak, we recommend you not to update.