What is Jailbrake, how can I do it.
I have a iBOOK G4 1.33 GHz with OS 10.4.11 and iTunes 9.2.1 I want to use my iPhone 3G with iOs 4.2.1 installed on my Windows XP Dell laptop POS with iTunes 10. something. I am going to wipe the Windows and start so that I will be able to use my Iphone with both of the Older systems. I want to put my iPhone back to the Older iOs. nothing else matters. just this information.