I'm sorry, but I don't own any Apple devices, so I can't give you any first-hand info. Perhaps someone else has.
But 2 things occur to me as possibilities:
1. The device is not maintaining a connection with the PC and windows thinks it has been removed.
2. The Apple driver
is not playing nice in a Windows system.
Some folks have reported these as a workaround:
First, with the ipod connected, restart the computer. Check the device again.
If that did not change anything:
With the ipod connected, go into Devices and Printers and Uninstall/Remove the device. Disconnect the ipod. Restart the system. Now plug the ipod in and let Windows install the driver again.
See if that changes anything for the better.