The following steps are for the iPhone 3G only using a Windows PC.  

Download the following the file below using the Firefox Browser which can be downloaded fromwww.firefox.com

Download File 2: Apple Firmware used for preparing for the jailbreak Click here to download

Note:  Save the File do NOT select open in iTunes

Please now select one of the following options:

Option 1: Click here if you use your iPhone on its original network

Option 2: Click here if you do NOT use your iPhone on its original network.