Unlock iPhone 4 – iPhone 3GS on 5.0.1
Step 1: Required Downloads
We strongly recommend downloading using the browsers Firefox, Chrome or Opera to avoid errors. If using Safari or Internet Explorer read this first and you may have difficulty when later browsing for the iOS ipsw file.
Click the link below or Right click and (“Save Target As…” or “Save Link As…”) to download the ipsw version software for your device. Important: Do not open the file, just save the file. This file will take 5 to 15 minutes to download, as it is 600-700MB in size. WAIT! DO NOT GO TO STEP #2 UNTIL THE FILE IS DOWNLOADED
Connect your iDevice with your PC via USB and open Redns0w you just downloaded above.
At this stage you will be presented with a screen where you will be guided on how to enter DFU mode. Quickly hold “Power” button and then while holding the “Power” button, you will now have to hold “Home” button too. Now after few seconds release “Power” button but keep holding “Home” button until installation begins.
Follow these instructions on the 3 screens below:
Continue holding the home button until iTunes pops up a message telling you that it has detected a device in recovery mode.
After the device has successfully entered DFU mode, your device will be black like this:
Note: It may take a few attempts to get your device into DFU mode. Generally, if you are still holding both buttons down and you see the Apple logo you are holding them down for too long!
Open iTunes then Restore your iPhone 4, 3GS to the Custom iOS 5.0.1 ipsw (the file name begins with NO_BB).
Now Open Cydia > Manage > Sources > Edit > Add then write the following repo :
After installing this repo, tab on search and search for ultrasnOw then install it.
Congratulation, now you have unlocked iPhone 4, 3GS on 5.0.1