Make sure not to update to iOS 4.3.5 if you need an unlock as one is not yet available. Also please note that this jailbreak is tethered for those on the new bootrom.
Step One
Create a folder on your desktop called Pwnage
Download RedSn0w 0.9.8b7b from here and place it in the Pwnage folder. Likewise, download the latest 4.3.5 firmware from below and place it in the same folder.
4.3.5 (3GS): iPhone2,1_4.3.5_8L1_Restore.ipsw
Extract the RedSn0w zip file into the same folder.
![How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5] How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5]](/images/tutorials/16267/58339/58339.png)
Step Two
Connect your iPhone to the computer and launch iTunes.
![How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5] How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5]](/images/tutorials/16267/56185/56185.png)
Select your iPhone from the list of devices on the left. Now hold down Shift and click the Restore button. Restore is preferred as it won't create any wasted space on your iPhone.
![How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5] How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5]](/images/tutorials/16267/56201/56201.png)
Navigate to the Pwnage folder on your desktop and select the 4.3.5 firmware ipsw. Click the Open button to continue.
![How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5] How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5]](/images/tutorials/16267/58340/58340.png)
Step Three
Once iTunes has finished updating your iPhone to the desired firmware open the Pwnage folder on your desktop and launch the redsn0w application from the redsn0w folder we extracted earlier.
**Windows 7 users need to run RedSn0w as an administrator in Vista compatibility mode. You can do this by right clicking the executable and selecting Properties from the contextual menu
![How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5] How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5]](/images/tutorials/16267/56184/56184.png)
Step Four
Once RedSn0w opens click the Browse button
![How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5] How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5]](/images/tutorials/16267/58345/58345.png)
Step Five
Select the 4.3.5 firmware ipsw we placed in the Pwnage folder on our desktop then click Open.
![How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5] How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5]](/images/tutorials/16267/58341/58341.png)
You will be prompted to indicate if this is a newer model of the iPhone 3GS. If you're not sure you can determine follow this tutorial to determine which bootrom you have.
![How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5] How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5]](/images/tutorials/16267/58342/58342.png)
Step Six
Once the firmware has been verified click the Next button to continue.
![How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5] How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5]](/images/tutorials/16267/58346/58346.png)
Step Seven
RedSn0w will now prepare the jailbreak data
![How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5] How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5]](/images/tutorials/16267/56193/56193.png)
Step Eight
From this window you can select the jailbreak options you would like. Make sure Cydia is selected and click the Next button to continue
![How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5] How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5]](/images/tutorials/16267/58343/58343.png)
Step Nine
Please plug your iPhone into the computer and make sure its OFF then click the Next button
![How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5] How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5]](/images/tutorials/16267/58347/58347.png)
Step Ten
RedSn0w will now guide you through the steps to get into DFU mode. You can find more help with DFU mode here
![How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5] How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5]](/images/tutorials/16267/58348/58348.png)
Hold down both the Home button and the Power button for 10 seconds.
![How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5] How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5]](/images/tutorials/16267/58349/58349.png)
Release the Power button and continue holding the Home button until RedSn0w detects the device.
![How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5] How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5]](/images/tutorials/16267/58350/58350.png)
Step Eleven
Your iPhone will now reboot
![How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5] How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5]](/images/tutorials/16267/58351/58351.png)
Step Twelve
RedSn0w will then begin uploading the new RAM Disk and Kernel.
![How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5] How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5]](/images/tutorials/16267/58352/58352.png)
Step Thirteen
Once this is complete you will be notified that RedSn0w is done. Click the Finish button. When your iPhone finishes rebooting (5 minutes or so) it will be jailbroken with Cydia on the SpringBoard.
![How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5] How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5]](/images/tutorials/16267/58353/58353.png)
*As usual a big thanks to the iPhone Dev-Team for their hard work and contribution to the iPhone community.
**Windows 7 users can try running RedSn0w as an administrator in Windows Vista or XP compatibility mode if you experience any difficulties.
BOOT TETHERED
Once RedSn0w has finished jailbreaking your device you will need to boot it tethered if you have a newer iPhone. Rerun RedSn0w and this time select Just boot tethered right now from the list of options instead of installing Cydia.
![How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5] How to Jailbreak Your iPhone 3GS Using RedSn0w (Windows) [4.3.5]](/images/tutorials/16267/58344/58344.png)