Jailbreak iPhone 3Gs 3.1.3 with Spirit & iTunes 126.96.36.199 on Windows 7
The following guide will help you jailbreak iPhone 3G and iPhone 3GS (all versions) untethered on the latest iPhone OS 3.1.3.
Step 1: Download Spirit for Windows.
Step 2: Connect iPhone with your computer, Run “Spirit” and then Click on “Jailbreak”:
Note for Windows 7 Users: Change the “Compatibility mode” to “Windows XP (Service Pack 3)” by right clicking on “Spirit.exe”, and then click on “Properties”. This can be seen in the screenshot below.
Also check: “Run this program as an administrator” option on the same window.
Step 3: Let the app do its thing and wait for the app to show “Jailbreak Complete!” message. At this point, wait for the iPhone to automatically reboot.
Step 4: Voila! You should now have a fully jailbroken iPhone 3G/3GS running on firmware 3.1.2 or 3.1.3 – Untethered !.