I love how you start piss fights in other threads because your lack of arguing skills is so horrid that you can't even back up your own statements in the previous thread.
OP, I'll give you the simplest of answers. You can get on 4.2.1 untethered with 4.2b3 SHSH save. You need to be a developer/pirate to get the 4.2b3 ipsw. You'll also need to download a program called Redsn0w. Search for the tutorials, it's not that difficult. HOWEVER, the untethered jailbreak does cost a price. This is a BETA and Redsn0w developers have warned and explicitly stated NOT to use their program to jailbreak. It's just for testing only. If you continue with the JB, iBooks does not work (but who really needs it) and some users have reported other bad things have happened. All in all, it's up to you if you want to do it.
I love how you start piss fights in other threads because your lack of arguing skills is so horrid that you can't even back up your own statements in the previous thread.
Thanks for you support and concern, maybe we can get together one day and you can teach me some "arguing Skills". My augment is well supported and documented on the other thread, that fact you don't agreed doesn't make my argument flawed.
BTW just for the records, i don't "start puss fight" anywhere, I started informative thread about an specific tool and some other "users" feels the need to trash it with nonsense about their fanaticism for some specific developer.