Oh the woes of the MP3 player......
I am aware that some players don't like it if you have plugged them into your PC prior to loading up the software provided with them & will subsequently not work even with it loaded up.
There may be a way of resetting your player by either a combination of button presses or using a dedicated reset button. But I'm sure this would be printed in the user manual.
Best of luck, you'll need it.
