It is normal that the phone loses connection during the reboot phase. If you wait for a while it will automatically reconnect to your PC. If you lose connection during the backup, installation or restore phase, please do the following:
- Disconnect the USB cable from your phone
- Press your phone’s power button for about 10 seconds
- Reconnect the USB cable
- Wait for the installation to continue
Note: If this doesn’t solve your issues, try to connect your phone to another USB port on your laptop or to a USB port on the backside of your desktop PC. In some cases rebooting the computer also helps or using another PC to do the update.
Try also this:
- Right click the Nokia Suite shortcut icon.
- Then click Run as administrator.
- Then continue your update.
If above does not help reinstall the Nokia Connectivity Cable Driver or Nokia Suite.