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I would try these steps from the article named:
iTunes: Specific update-and-restore error messages and advanced troubleshooting
This error occurs when the device unexpectedly loses its USB connection with iTunes. This can occur if you manually disconnect the device during the restore process. You can resolve this issue by using USB troubleshooting, using a different Dock Connector or Lightning Connector to USB cable, trying another USB port, restoring on another computer, or by eliminating conflicts from third-party security software.
All the very best,