I have my Yamaha CP300 keyboard connected to my computer via a USB connection. I have the drivers installed for the Yamaha. Yet I don't see it show up as a device on my computer, even though when I turn it on and off I hear the noise that means a portable device has been plugged into and unplugged from the computer. How do you get files from the keyboard onto your computer? I don't have the manual with me, I tried reading it online, and it wasn't in the least bit helpful.