After passing a long way to jailbreak iOS 5.1 using Sn0wBreeze 2.9.3 now you can unlock iOS 5.1 using ultrasn0w fixer. This unlocking method is very fast and easy. Just follow this simply steps to unlock iOS 5.1.

How to unlock iOS 5.1 using Ultrasn0w Fixer On iPhone 4,3GS

When you start Cydia first make these easy steps by using the link how to install ultrasn0w 1.2.5. And after that we can continue to unlock iOS 5.1. Also you need this info where you can find if your gadget is compatible for this unlock. Now after you have Ultrosn0w fixer installed you should reboot your iPhone. 1. Start Cydia, go to Source and add http://repo666.ultrasn0w.com. Usually it must be included already. Once you have included the source, go to search, search for ultrasn0w and set it up. 2. Right after installation you will notice a button that requires you to reset the gadget to apply ultrasn0w alterations. Since all of us have tethered jailbreak, for now, ought to continue with the actions below to restart your terminal. Mobilesubstrate stops restarting the gadget hence the display will simply show the Apple logo as soon as the iPhone will reset. 3. When the logo press at the same time the Home and Lock buttons and keep them pressed for Ten seconds. During these Ten seconds the terminal will restart and Apple logo will fade away from the display screen. After Ten seconds release the Lock button and hold the Home button for the next Fifteen seconds and the terminal will start in tethered mode. 4. Having got the terminal in DFU Mode should reboot iBooty 2.3 and the program will start your gadget in tethered mode and then you are able to use Cydia. As it is a tethered jailbreak, you should do steps 3 and 4 each time you reboot your terminal or else you won't be able to work with it. I know that it is an inconvenience but you should do this if you want to unlock iOS 5.1 using Ultrasn0w fixer.