How to Jailbreak Iphone or Ipod Touch ios 4.2.1

How to jailbreak any iphone or ipod touch running ios 4.2.1 firmware. This is a tethered jailbreak, meaning that any time you turn off or reboot your iphone/itouch, you have to plug it into the computer and redo the jailbreak.

Firmware download Link : http://www.iphonedownloadblog.com/iphone-downloads/


Redsn0w download link: http://www.iphoneworld.ca/news/2010/12/04/download-redsn0w-0-9-6b6-iphone-jailbreak-now-with-sam-support-windows-mac/