Jailbreak and Unlock iPhone 3.1.2 Firmware on Windows

PwnageTool 3.1.4 has been released and is for Mac OS X users only. The following step-by-step tutorial/guide will help you in running fully unlocked and jailbroken iPhone 2G,3G and 3GS with iPhone firmware 3.1.2 using your Windows PC without having to wait for Windows version of PwnageTool or redsn0w. Mac version of the tutorial can be found here.
If you don’t care about the unlock and just want to jailbreak your iPhone on 3.1.2, then you can also alternatively follow the guide posted here to jailbreak your iPhone on Windows with blackra1n in just 30 seconds.

Step 1: Make sure you have downloaded and installed the latest version of iTunes.
Step 2: Now connect your iPhone with your PC. You must connect it to a single usb port on the backside of your computer. Do not use any usb hub or the ports in the front as this could result in an error during update process.
Step 3: Start iTunes. Sync your iPhone with your PC so that iTunes backs-up all your important data including settings, apps, music, contacts and photos.
Step 4: As a Windows user, you will have to now download a custom firmware for your iPhone which has been cooked on a Mac using PwnageTool 3.1.4. Don’t ask us for the download links for these custom firmware files for the obvious reasons. Just Google it:

• For iPhone 2G: “iPhone1,1_3.1.2_7D11_Custom_Restore”
• For iPhone 3G: “iPhone1,2_3.1.2_7D11_Custom_Restore”
• For iPhone 3GS: “iPhone2,1_3.1.2_7D11_Custom_Restore”

and use one of the torrent links to download the custom created .ipsw file
Step 5: Once you have downloaded the required .ipsw file, Move it into the following location depending on which version of Windows you are using:
“C:\Users\[username]\AppData\Roaming\Apple Computer\iTunes\iPhone Software Updates\” (Windows 7)
“C:\Users\[username]\AppData\Roaming\Apple Computer\iTunes\iPhone Software Updates\” (Windows Vista)
“C:\Documents and Settings\[username]\Application Data\Apple Computer\iTunes\iPhone Software Update\” (Windows XP)
Note: Make sure you have enabled “Show Hidden Files and Folders” option in Tools->Folder Options.. –> View tab found in Windows Explorer to see the directory locations mentioned above.
Step 6: Restart iTunes. You will now be prompted to install the new firmware 3.1.2 from iTunes. DO NOT UPDATE from this prompt. Just close this dialog by clicking on “x” from the top right-most corner of the window.
Step 7: Now you will have to restore your iPhone to this custom firmware 3.1.2 that you have just downloaded for your iPhone. Click on your phone from the sidebar in iTunes to get to this screen as shown in the screenshot below:

Step 8: Press and hold left “Shift” button on the keyboard and then click on “Restore” (Not “Update” or “Check for Update”) button in the iTunes and then release the “Shift” button.
This will make iTunes prompt you to select the location for your downloaded custom firmware 3.1.2. Select that custom .ipsw file and click on “Open”.

Step 9: Now sit back and enjoy as iTunes does the rest for you. This will involve a series of automated steps. Be patient at this stage and don’t do anything silly. Just wait while iTunes installs the new firmware 3.1.2 on your iPhone. Your iPhone screen at this point will be showing a progress bar indicating installation progress. After the installation is done, iPhone will restart automatically and you should now have a fully jailbroken iPhone running on firmware 3.1.2.
How to: Unlock iPhone on 3.1.2 Firmware:
You can now follow the tutorial/guide posted here to unlock your iPhone 3GS or iPhone 3G on firmware 3.1.2 using ultrasn0w.
Step 10: Once you are done with the unlocking and jailbreak process. You can now restore all your settings, apps, music, contacts and photos to the newly installed firmware version 3.1.2 by restoring the backup that you made in Step 2 from iTunes.
UPDATE 1: Follow the step-by-step guide posted here to fix missing carrier name or logo on your unlocked and jailbroken iPhone 3G/3GS running firmware 3.1.2.
UPDATE 2: Follow the step-by-step guide posted here to Enable Tethering on iPhone 3.1.2 Firmware.
UPDATE 3: You may also like to check out How to: Patch MobileInstallation File on iPhone 3.1.2 Firmware.
UPDATE 4: Native MMS functionality in Messages app on iPhone 2G can now be enabled using the step by step guide posted here.
UPDATE 5: Fix Push Notifications on Hacktivated iPhone 2G/3G/3GS running iPhone firmware 3.1.2 can be found here.
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Feel free to ask me any question here should you run into any problem during the update process.
Disclaimer: This guide is for testing & educational purposes only. Follow it on your own risk. I’m not responsible for any loss of important data or malfunctioning of your iPhone.
Download iTunes 9.0.1 for Windows