Error message "disk not available" .

With iTunes open I plug in my iPod to sync. Windows "plug n play" recognizes the device and the icon appears in iTunes. Seconds after being plugged in the iPod will eject itself but the icon will still display in iTunes. When attempting to sync the iPod iTunes displays an error message "disk unavailable" and in some cases will freeze. I have completely uninstalled and reinstalled iTunes and rest the iPod, I've also tried USB 2.0 and 3.0 ports and the problem persists.