Instructions: Jailbreak Verizon iPhone 4.2.6 on Windows + install MyWi WiFi tethering
Here is how I just jailbroke my new Verizon iPhone and successfully installed MyWi WiFi tethering with GreenPois0n on Windows XP or 7. We're not responsible for any damage done to your phone by Jailbreaking.
1) Activate phone with iTunes using the instructions provided with the phone. I also upgraded to OS 4.2.6. Some phones are already shipped with 4.2.6.
2) On your Windows computer, download GreenPois0n at greenpois0n.com . I used version RC5.b4
3) Extract the greenpois0n.exe file in the zip/rar you downloaded, and place it on your desktop
4) Right mouse click on the greenpois0n icon on your desktop and select "Run As Administrator" (Windows 7) or "Run As" (XP) You need to run greenpois0n as Administrator. If you are prompted for a password and
do not know the Administrator password of your computer, you are out of luck.
5) Connect the iPhone to your computer and press the top button on the phone for two seconds, then turn the phone off by sliding the switch on the screen
6) On the GreenPois0n window, click the Prepare to Jailbreak DFU button. Follow the instructions. You will be prompted to push the top button for two seconds, push the home button (the button on the bottom of the screen) for 10 seconds while holding down the top button, then release the top button while holding down the home button. When the window says "Jailbreaking:", you can release the home button.
7) You will see green bars on the GreenPois0n window. The phone will go completely white. The phone will start showing many lines of text messages. If instead GreenPois0n shows "Jailbreak failed ", you may not have run it as Administrator.
8) When the GreenPois0n window says "Jailbreak complete", you should see a green icon on the phone that says "Loader". You need to be connected to either WiFi or Verizon's network. Press the Loader icon. This installs Cydia, which is how jailbroken apps are installed on your phone.
9) Press the Cydia icon. Answer the prompts, then wait while it loads. It may also ask you to upgrade the software; do so if prompted. For me, the phone timed out to the Lock screen. You can see that Cydia is still running if you unlock the phone and press the Home button twice; the icons at the bottom of the screen will show what applications are running. (You can stop running applications by pressing one of those icons and holding down your finger until a red X appears, then pressing the icon. Don't do that at this point).
10) Go back into Cydia, click the Search button at the bottom of the screen, and search for "MyWi".
11) Click the MyWi 4.0 icon and install it. I purchased it through PayPal for $19.95, but I believe there is also a free trial. Do not use a cracked version.
12) After MyWi is installed, click the MyWi icon and select Laptops. Select Fastest Setup WiFi Hotspot.
13) click WEP Security, click ON, and enter a 10-character WEP key. You can use numbers 0-9 or letters A-F.
14) Go back to the WiFi Hotspot setup screen and make sure WiFi HotSpot is ON.
15) An iPad or iTouch should be able to connect to the WiFi called "xxxx-iPhone-MyWi". On your Windows machine, you may need to do one extra step. Go to the Control Panel and click Network Connections or Network and Sharing Center.
16) Right mouse click on your Wireless Connection (XP) or click on your Wireless connection (Windows 7) and select Properties.
17) Click the Advanced (XP) or Sharing (Windows 7) tab. Make sure that "Allow other network users to connect through this computer's internet connection" is checked. Click OK.
18) In your wireless setup window (each computer has a different one), there should now be a WiFi connection called "xxxx-iPhone-MyWi". Connect to it. Enter the key you set in step 13 above. You should now be connected to the internet with an Ad Hoc connection. This will use the data plan that is on your Verizon account.