If you have not already, shut down (power off) your computer. Use this procedure to reset iPod shuffle.
Start up computer, with shuffle NOT connected. Run iTunes. Connect shuffle.
If you were connecting the shuffle to a USB hub, try using a direct port on the computer. You may also want to try disconnecting all other USB devices, except for standard mouse and keyboard, then connect shuffle.
if all else fails, uninstall itunes and all it's components in order as such:
- Apple Software Update
- Apple Mobile Device Support
- Apple Application Support (iTunes 9 or later)
Then download the latest version at www.apple.com/itunes....it is important that you uninstall in that order.