Launch iTunes. It should report that it has detected an iPhone in Recovery Mode key (Windows) or key (Mac) and click the button in iTunes. Browse for and select your Custom iOS 4.0/4.1 IPSW
(short for "iTunes Restore Error Bypasser") is a specialized lightweight desktop utility designed to assist users in bypassing common errors—specifically 1600, 1601, 1602, 1603, and 1604 —encountered during the restoration of custom iOS firmware. Developed by the well-known developer iH8sn0w , iREB prepares Apple devices like iPhones, iPads, and iPod Touches for a clean restore by placing them into a specialized "Pwned DFU" state. Core Functionality and Supported Devices ireb 40x 41 rc2zip 1 hot
Some users need to ensure their computer can communicate with Apple's servers or a Cydia server. You may need to comment out lines containing gs.apple.com in your hosts file (located at C:\Windows\System32\drivers\etc\hosts 2. Enter Pwned DFU Mode Close iTunes before starting. Open iREB and select your specific device model. Follow the on-screen instructions to enter buttons together for 10 seconds. Release the button but continue holding until your computer detects a new USB device. Launch iTunes