But first a few comments: If you have an unlocked phone, DO NOT use this jailbreak. In fact, if your phone is unlocked, should avoid completely iOS 4.2.1.
Jailbreak is also a captive. This means that you must connect your device to your computer every time you reboot, to maintain the functionality of your RedSn0w jailbreak and run. This concerns some of the most recent IOS devices like the iPhone 3G (new bootrom) iPad, iPod Touch 2G (Model TM) 3G and 4G iPod Touch iPod Touch and IPAD. Meanwhile, older devices like the iPhone 3G and iPod Touch 2G (non-MC-model) using an untethered jailbreak.
That said, we go.
1) Take the jailbreak of one of the following RedSn0w download:
Mac - Redsn0w_mac_0.9.6b4.zip
Windows - Redsn0w_win_0.9.6b4.zip
Files can be found at the following sites. We propose to create a new folder with a convenient name like "Jailbreak" with a copy of the ipsw.- Mac OS XiPhone ~ / Library / iTunes / iPhone Software UpdatesiPad ~ / Library / iTunes / IPAD software UpdatesiPod touch ~ / Library / iTunes / iPod Software Updates
Note: The tilde "~" represents your home directory.
- Windows XPiPhone C: \ Documents and Settings \ [username] \ Application Data \ Apple Computer \ iTunes \ iPhone Software UpdatesiPad C: \ Documents and Settings \ [username] \ Application Data \ Apple Computer \ iTunes \ iPad Touch Software UpdatesiPod C: \ Documents and Settings \ [username] \ Application Data \ Apple Computer \ iTunes \ iPod Software Updates
Note:If you don't see the Application Data folder, you may need to show hidden files.
- Windows 7 and VistaiPhone C:\Users\[username]\AppData\Roaming\Apple Computer\iTunes\iPhone Software UpdatesiPad C:\Users\[username]\AppData\Roaming\Apple Computer\iTunes\iPad Software UpdatesiPod touch C:\Users\[username]\AppData\Roaming\Apple Computer\iTunes\iPod Software Updates
Note: If you don't see the AppData folder, you may need to show hidden files.
3) You should see the following message:
4) Choose "Install Cydia 'and press the following:
5) Make sure your iPhone or iPod Touch is turned off and connected to the computer before touching the side, as shown below:
6) after hitting the next, putting a guide driving device in DFU mode. Follow the instructions carefully.
7) Sit back and watch the pretty progress bar:
8) Finally, the following message:
9) If you have one of the new devices like the iPhone 3G (new bootrom) 4 iPhone 2G (non-MC model), 3G, 4G, iPad and want to keep the jailbreak and RedSn0w use features, you will need to connect your device and run RedSn0w and check out "Simply start a captive now." Otherwise, your applications jailbreak does not work.
10) Many users have noticed that Cydia does not seem to work when they completed the jailbreak installation. This is because you must restart your iPhone or iPod Touch and select that "just boot attached now" option. When you start in this way Cydia work. Please note that from now on, you must start on the path to your jailbroken apps work. Hence the name "captive" jailbreak, which literally means your unit must be connected to your computer every time you turn it on. (Do not confuse with the awakening of your iPhone to be asleep or in standby). Unfortunately, this is the only way to do it now. This is why many take to jailbreak in bulk. We hope that clears things.
also read more about Redsnow Jail Break
