How to JAILBREAK 4.2.1 iOS Greenpois0n RC5 2 UNTETHERED for ALL iPhone, iPod Touch, iPad

This video will show you how to Jailbreak iOS 4.2.1. I have added some troubleshooting tips and have attempted Greenpois0n multiple times using this method. It worked for me, so as long as you follow the steps very carefully, you should be okay.

Supported iDevices:

- iPod Touch 2G (all bootroms)
- iPod Touch 3G
- iPod Touch 4G
- iPad 1G
- iPhone 3Gs (all bootroms)
- iPhone 4
- iPhone 4 Verizon (_not_tested_)
- AppleTV 2

Make Sure:

- Your Device is restored to 4.2.1 CLEAN DFU (except those preserving baseband)
- You have Greenpois0n from the official source or one of the mirrors below
- Anything that blocks connections in or out should be turned off or allowed for Greenpois0n (like Little Snitch)
- You have internet connection

Other things:

- My phone was activated with an AT&T Sim card
- Sync'd to a new profile on iTunes

Steps:

1. Restart your Mac
2. Plug in your iDevice after your Mac has restarted
3. Kill iTunes if it opens
4. Open Greenpois0n RC5 2
5. Hit Jailbreak and get ready
6. Follow the on screen instructions for DFU mode, make sure you do them on time!
7. CONTINUE HOLDING THE HOME BUTTON UNTIL YOU SEE SCROLLING TEXT!
8. You should be Jailbroken with the Loader app on your homescreen
9. Open up Redsn0w
10. Find your 4.2.1 iPSW
11. Click Next
12. Check mark INSTALL CYDIA
13. Contine the steps of Redsn0w
14. Your device will reboot and now your are Jailbroken on 4.2.1 with Cydia!