mohd yusuf ansari, lets start off trying what Apple suggest:
"This error is often related to USB timing. Try changing USB ports, using a different dock connector to USB cable, and other available USB troubleshooting steps (troubleshootin
If the issue is not resolved by USB isolation troubleshooting
Connect the device to iTunes, confirm that the device is in Recovery Mode. If it's not in Recovery Mode, put it into Recovery Mode.
Restore and wait for the error.
When prompted, click OK.
Close and reopen iTunes while the device remains connected.
The device should now be recognized in Recovery Mode again.
Try to restore again.
If the steps above do not resolve the issue, try restoring using a known-good USB cable, computer, and network connection." Let us know what works for you.