Thank you for the update, passionflower
I think next would be a good idea to shutdown the computer, and disconnect everything from it. Let it sit for a minute or two, then plug it all back up and turn the computer on, then try again.
Next I would start troubleshooting the USB ports on the computer. I would start with this troubleshooting.
- On the Start menu, click Control Panel.
- Double-click the System icon.
- Click the Hardware tab.
- Click Device Manager.
- Scroll down the list of devices to the Universal Serial Bus controllers
- Click the plus ➕ icon next to the Universal Serial Bus controllers.
- Double-click one of the indented USB Root Hub entries.
- Click the Power Management tab.
- Deselect the "Allow the computer to turn off this device to save power" option.
- Click the OK button at the bottom of the window.
- Restart the computer.
From: iPod not recognized when connected to Windows laptop over USB
http://support.apple.com/kb/TS1401
And then this troubleshooting
- Plug the device directly into a high-power USB 2.0 port on the computer. If possible, use a USB port on the back of the computer.
Avoid plugging the device into a keyboard, display, or standalone hub. The USB ports on these accessories may be low-power or only offer USB 1.x connections.
- If you are using an accessory, remove the accessory and connect the device to the computer using only the Apple 30-pin to USB Cable or Lightning to USB Cable.
If you have access to additional Apple 30-pin to USB Cable or Lightning to USB Cables, try testing with another if the first one doesn't work.
- Restart your computer and device. To restart your device:
Hold the power button until "slide to power off" appears. Slide to power off your device. When it is off, press the Sleep/Wake button to turn it back on.
- Disconnect all USB devices from your computer, except for your keyboard and mouse. Then reconnect the iOS device. If the issue is resolved, reconnect other USB devices, testing after each connection.
From: iOS: Troubleshooting USB connection
http://support.apple.com/kb/TS1286
If you have another computer you can also test the iPod Nano there to help isolate whether the issue is with the iPod or the computer.
And just in case the issue is still not resolved, I want to thank you for using the Apple Support Community. Due to the nature of your issue you may find more information by using another one of Apple's support resources - https://expresslane.apple.com/GetproductgroupList.action.
All the very best,
Sterling