USB Device Not Recognized

I went to plug in my Leonardo Arduino today and I get this message "USB Device Not Recognize". In Windows 7 device manager, it is listed as "Unknown Device". I've tried updating the driver, uninstalling/reinstalling the driver - each time pointing to the Arduino Driver folder. Each time the result is the same - "The Best Driver software for your device is already installed". I've tried all the other USB ports - same problem. I've tried rebooting the computer - same problem. Pressed the "reset" button on the Arduino - same problem. There is also nothing listed under "PORTS" in the device manager and the "tools/serial port" Arduino menu option is ghosted out. I've always kept the Arduino in it's original packaging when not in use. I can't imagine something went wrong with it. The last time I used the Arduino was about 4 days ago - and it worked perfectly then and it was kept in it's original box the whole time.

I'm out of ideas - any thoughts?

Thanks in advance!