What does power surge on hub port mean?

When I plug my iPod into my laptop a message comes up saying "A usb device has malfunctioned and exceeded the power limits of its hub port. You should disconnect the device." and then under reccomendation it says "To reenable the port, disconnect the hardware and click Reset. If you click Close, the port will no longer function" and I've clicked everything and kept unplugging my charger and plugging it in a different plug and I restarted my laptop but it keeps coming up with the message and I don't know what's happeneing or what to do