How to Jailbreak Apple iPhone 4 iOS 4.2.1

Last time we saw on how to jailbreak the Apple iPad, now let’s see how you can jailbreak the Apple iPhone iOS 4.2.1 by using Pwnage Tool. Before proceeding to jail break your iPad, you will have to make sure that you have downloaded and installed all the softwares like Apple iTunes, iOS 4.2.1 GM for iPhone 4 and also the latest  Pwnage Tool 4.1.2.

Procedure to jailbreak Apple iPhone 4:

• Firstly you need to Sync iPhone with Apple iTunes and create a back up of all your data, including music, contacts, pictures, calendar, notes, messages, apps, etc. So that all your data will be backed up, just in case if anything happens your data will be safe.

• Now, move all installed files mentioned above to the Desktop as a shortcut and right click on the Pwnage Tool 4.1.2 icon and select on option Show Package Contents.

• Now, navigate to Contents/Resources/FirmwareBundles/ and paste iPhone3,1_4.2.1_8C148.bundle file in this location and close this folder.

• Now all you will need to do is to just launch Pwnage Tool and it will detect i OS 4.2.1 GM for iPad automatically.

• If a message box reads out Do you have an iPhone contract that would activate normally through iTunes? Then simply click on No. If you select Yes, then it will update your base band to the latest version. Only select Yes, if you are on official at&t carrier.

• Now, Pwnage Tool will now create the custom .ipsw file in your Apple iPhone 4 which will be jailbroken. You will be prompted to save custom .ipsw firmware file, you need to save it on the desktop. It will take around 10-15 minutes for building the custom firmware.

Now, you will need to restore your Apple iPhone 4 to the custom firmware 4.2.1 GM.

• Now connect you iPhone to the system and open the latest i Tunes and select the iPhone from the right bar of the window side bar and just click on restore while holding the ALT key which is located on the MAC/ Shift key on the Window.

• Just select the the custom iOS 4.2.1 which has been created by Pwnage Tools and then iTunes will do the rest of the process automatically by itself

• Now you need to select the Custom IPSW that was created earlier and click the Choose button. Wait for a while till iTunes installs the new firmware 4.2.1 GM on your iPhone 4. As soon as installation is done, iPhone 4 will restart automatically.

You have now successfully jailbroken the iPhone which is running iOS 4.2.1 GM on 1.59.00 base band! Now you can use ultrasn0w to carrier unlock your Apple iPhone 4. With the help of Pwnage tool you can unlock iPhone 3G, 3GS or iPod 2G too.