Upgrade and jailbreak iOS 4.2.1

The iPod touch that I have came with 3.1.3 and when iOS 4 was announced I upgraded it to 4.1; that’s as far as I went . With the recent announcement of greenpoisOn’s untethered jailbreak for 4.2.1, I decided to upgrade the iPod.

 

Before upgrade

Backup via iTunes

1. As a rule of thumb always do a backup before messing around with the OS. Just connect the device to iTunes, right click on it and select “Back Up” and let iTunes do it’s magic.

If you have previously jailbreak your device and already have loads of apps installed via Cydia, make sure you backup that as well. There are several methods of doing so but the two easiest ones are via aptbackup or pkgbackup. Both can be downloaded via Cydia though please take note that pkgbackup is a paid app. Based on some of the forums I’ve been reading seems like pkgbackup is a more reliable solution though it’s still not a 100% guarantee.

New device or restore

2. After the backup, click on “Update” to download and install the new firmware.

3. Once the device is upgraded, iTunes will prompt to setup the device as new or restore from a backup, choose “Set Up A New ..” and continue, cancel the sync and eject the device.

4. Click here to download greenpois0n for MAC or WINDOWS.  Save the file to your computer desktop.

5. Locate the file and open the application. You may need to extract/unzip the file.

Finally Greenpois0n for iOS 4.2.1 on Windows

Greenpois0n

Recently an updated version of the the Greenpois0n tool became available for Mac users and allowed for untethered jailbreaking of iOS 4.2.1 devices. Now Windows users are finally able to get in on the fun as well.

As Engadget points out, the official Greenpois0n website is not able to keep up with the volume of happy Windows users at the moment, so here’s a download mirror link that’s a bit more likely to work right now. [via Engadget]