However, I would like to share a
guide on how to jailbreak iphone 3Gs 3.1 firmware on Windows using Custom Firmware (iPhone2,1_3.1_7C144_Custom_Restore).

How to Jailbreak iPhone 3G Firmware 3.1

1. First Download the following links of custom iPhone 3.1 Firmware
2. Now join all the downloaded parts using HJSplit and you will get one archive, uncompress that archive and it contains IPSW file of firmware 3.1
   Custom iPhone 3GS 3.1 Firmware Part 1
   Custom iPhone 3GS 3.1 Firmware Part 2
   Custom iPhone 3GS 3.1 Firmware Part 3
   Custom iPhone 3GS 3.1 Firmware Part 4
3. Now Install (if you haven’t already) and open iTunes 9
4. Connect you iPhone to the PC using data cable.
5. Choose your iPhone from devices menu on left.
6. Now click “Resotre” while holding Shift key and select the custom IPSW file which you downloaded in step 1
7. Now Sit back and relax until the installation process complete.
8. After Jailbreaking your
   iPhone 3GS to 3.1 Firmware you can follow this guide to unlock you iPhone and use with any SIM/Carrier.

using latest Pwnage tool 3.1.3 which was just released by iPhone Dev Team.

Before you start with it here is what you’ll need in this guide.

1. iTunes 9
2. Pwnage Tool 3.1.3
3. Original iPhone 3GS OS 3.1 Firmware File

How to Jailbreak iPhone 3GS 3.1 Firmware:

1. Download and Install iTunes 9 from Apple site.
2. Make complete backup of your iPhone.
3. Download Original iPhone 3.1
   Firmware using the links provided in this post.
4. Download Pwnage Tool 3.1 and select
   iPhone 3GS from device list.
5. Now Pwnage tool will automatically detect original
   firmware file which you downloaded in Step 3, if it can’t then browse it manually.
6. Click Next and then Choose Yes and then on another dialogue box Choose no, if you aren’t using Contract iPhone. Choosing No will let you unlock your iPhone and use it with any SIM
7. Now Pwnage Tool 3.1 will start building custom IPSW file.
8. Once done, click Yes and then click Next.
9. Now Open iTunes 9 and choose your
   iPhone 3GS from the devices list on left side now press Alt/Option key and then click on Restore and browse the Custom made iPhone 3.1
   firmware now choose Open.
10. Now relax back until iTunes updates your iPhone to 3.1
    Firmware.

After completing the entire above steps your