If the standard reset above does not work and the iPod is not showing up in iTunes on your 64-bit machine, you may need to force the driver installation. This simulates what the old "iPod Reset Utility" used to do.
The utility relies on backend iTunes hooks. Modern 64-bit iTunes versions often conflict with legacy 32-bit tools. Finding the 64-Bit Version ipod reset utility 64 bit
The iPod Reset Utility clears the entire storage drive of your iPod and installs the latest compatible device firmware. Unlike standard syncing software, this utility bypasses normal system checks to force a hardware reset. Supported Devices If the standard reset above does not work