o Whom May Concern, the Dev-Team Blog has release a new redsn0w version 0.9.6b4 (based on Geohot’s Limera1n bootrom exploit) which can jailbreak the latest Apple iOS 4.2.1 (added with new feature like AirPrint and AirPlay to all iOS devices) which released on Monday. Here go the step:
Step 1. Back Up Your SHSB Blob
It’s advisable to backup your SHSB Blobs for the future, before you use any new jailbreak as you could easily restore it back to the original condition prior to the jailbreak if anything happen. For the step to back up the SHSB Blobs, please follow the guide as show in the video: How To Backup SHSH Blobs/Files On iPhone/iPad/iPod Touch JAILBREAK SPIRIT
Step 2. Please make sure that your iTunes is of the revision 10.1 before you proceed to the iOS 4.2.1 update. You can download iTunes 10.1 (http://support.apple.com/kb/DL1103
) at Apple website or you can update your iTunes through the apple software update.*Notes: iOS 4.2 is compatible with the iPhone 3G, 3GS, and iPhone 4, the iPod touch 2nd, 3rd and 4th generations, and the iPad.
Step 3. Download the redsn0w software at Dev Team blog or any of the link below:
Step 4. Run Redsn0w.exe*Notes: If you’re using windows 7, you will have to use redsn0w in “XP Compatibility” mode.
Step 5. Click on browse and select the iOS 4.2.1 IPSW file. Refer to the location for your operating system:
* Mac OS X: /~/Library/iTunes/iPad Software Updates (or iPhone/iPod Software Updates, as the case may be)
* Windows 7 or Vista: C:[username]AppDataRoamingApple ComputeriTunesiPad Software Updates (or iPhone/iPod Software Updates)
* Windows XP: C:Documents and Settings[username]Application DataApple ComputeriTunesiPad Software Updates (or iPhone/iPod Software Updates)
Step 6. Click Next once the IPSW file is identified.
Step 7. Allow the kernel to be patched and click Next.
Step 8. Select “Install Cydia” and click Next.
Step 9. Ensure that your device is turned off.
Step 10. Follow the on screen instructions as below to put your iPhone into DFU mode.
[/img] i. Hold down the Power/Sleep button for 3 seconds.
ii. Without releasing the Power button, also hold the Home button for 10 seconds.
iii. Without releasing the Home button, release the Power button but Keep holding the home button for another 15 seconds.
Step 11. Next just wait until redsn0w completed installing the IPSW file on your iPhone, iPad or iPod Touch.
Congratulation! That all about it, you have managed to jailbreak your device.