Update: For iPhone 1st generation / 2G running 3.1.2 go here.
Here, are the steps to jailbreak and unlock iPhone 3G/3GS running on OS 3.1.2 modem firmware v 5.11.07 with blackra1n:
Before starting these steps, make sure you’ve updated to OS 3.1.2 from iTunes
- Open blackra1n.com on your Internet browser.
- Now click on the Windows Logo, to download the Windows version.
- Save the blackra1n.exe and Plug your iPhone.
- Once it is saved, right click and select open, or you can also browse to the path where you saved it and open the exe.
- As soon as you launch the blackra1n.exe, you will see a big button with caption ‘make it ra1n‘, click on that button.
- Now your phone will be entered in a DFU mode, and you will see Geohot’s photo on your iPhone screen and in the meantime you will also see iTunes saying to restore the phone: just ignore it.
- Let your iPhone reboot.
- Once it is rebooted, you will see blackra1n on your iPhone screen, open it.
- Now you will see 3 things: Cydia, Rock and sn0w.
- Tap on sn0w, but before doing that makesure you are connected to WIFI.
- It will install blacksn0w and will unlock the network.
- Similarly, again launch blackra1n and install Cydia and if you want Rock select it.
- That’s when you are done, You will also see your Carrier name.