Actually, i think what you mean is through the USB port right?
If it is your USB port do two either two things
1. Check to see if your MP3 Player only runs with a USB 2.0(hardware) (USB 2.0 hardware can be or come preinstalled in newer models of motherboards)
2. Check for updates for your USB port (Control Panel -> System -> Hardware Tab -> Device Manager -> Universal Serial Bus Controllers. From there either check and see if your MP3 Player is listed or just select a usb port, then right click, and update.
Maybe that could be your problem