i have an iphone 3gs jailbroken with blackra1n and unlocked ,
new bootrom, ios 3.1.2 7D11,shsh from 3.1.3 to 4.2.1saved .
i want to have an untethered jailbreak and unlock,i dont have the original carrier sim (at & t).
what ios can i upgrade and jailbreak and unlock without original sim n how.
i have pc on windows 7
Get a friend with a mac to make a custom 4.1 IPSW with pwnagetool 4.1.2 - make sure that it has activation turned on (baseband update is automatically prevented with this version of pwnagetool)
Originally Posted by pranavnayyar
get them to send you the custom IPSW then get a copy of redsn0w 0.9.6beta
Then use this guide:
iClarified - iPhone - How to Jailbreak Using a Custom Restore IPSW and RedSn0w (Windows)
Keep in mind that the images in this guide refer to an iPhone 4, but the process is the same for a 3GS, when redsn0w asks for an IPSW you must use an iPhone2,1_4.1_8B117_Restore.ipsw downloaded from the links on this page: http://www.hackint0sh.org/f127/22056.htm
Do not ask about any other iOS version. For the 3GS with new bootrom this technique only works for iOS 4.1