iOS 4.2 was released earlier today. Just like iOS 4.1 and iOS 4.0.2, the new iOS 4.2 at the moment is not jailbreakable. It also contains new baseband for all iOS devices which currently makes it impossible to unlock using existing version of unlocker. So if you rely on a jailbreak and unlock, stay away from this new firmware until new jailbreak and unlock tools are available for download.
If you upgraded to iOS 4.2 and now want to downgrade back to iOS 4.1 / 4.0.2 or 4.0.1, follow the instructions posted to downgrade iOS 4.2 on iPhone 4, 3GS, 3G, iPod touch and iPad to iOS 4.0.x. This guide will only work if you have SHSH blobs saved for the respective firmware you downgrading to.
Related Posts
- How to Downgrade iPhone iOS 4.1 to 4.0.1-4.0.2
- Resolve error 1015 during the downgrade the firmware for Mac OSX
- Spirit Untethered Jailbreak 3.1.2 – 3.1.3 iPad, iPhone, iPod is Released