To activate any idevice (iPhone, iPad etc) on iOS 4.3 via iTunes, you need to have UDID of your idevice registered on a developer account with Apple. But there are two methods floating around the web which can allow you to hacktivate (activate) iOS 4.3 on iPhone without having a developer account.
Neither we tested it and nor we recommend others to use this method if they haven’t enrolled themselves in the iPhone Developer Standard or Enterprise program.
However if you want to test these methods for educational purposes only, here are the instructions.
Quick Guide on how to “hacktivate” iOS 4.3 without a developer account.
1) Install iOS 4.3
2) “Jailbreak” with redsn0w 0.9.6rc8, you should see a white block in de upper left corner from your iPhone, reboot it
3) get iFunBox
4) navigate to “Raw File System” -> /System/Library/CoreServices
5) open SystemVersion.plist and remove the following lines:
6) Reboot the iPhone
7) Activate your iPhone with iTunes
2. Method (thx to joshingknight)
1) Restore to 4.2.1
2) Shift-Update and point the 4.3 IPSW. here’s important that you Shift-Update, not Shift-Restore!
If you want File System Access just jailbreak it like you were on 4.2.1 and reboot your iDevice when it’s stuck on a black screen, then you have FS Access with tools like iFunBox, but Cydia won’t work
Congrats your iPhone is activated now =)
Greetings from Switzerland..
Now a word of warning. If you do this and then go to settings and do any of the restore settings under restore and then connect to iTunes it will tell you that you can’t use the beta and need to be a registered developer. This how I know my UDID is not registered.
Note: This guide is posted for educational purposes only. And if you rely on unlock, don’t use these methods because the baseband on iOS 4.3 also gets updated and you won’t be able to unlock your device even if you downgrade iOS 4.3 to iOS 4.2.1 or iOS 4.1.