try it again ..
you have the same player design ?
hold "+" and switch on the player at the same time (both buttons) !
if the player starts (welcome picture or so), leave both buttons ..
the player will freeze now on starting picture, no button will work.
connect usb from player to pc .. if first session, windows will ask you about driver.
.. now you can see 3 new drives/partitions on your workspace.
after save/backup this drives, disconnect usb line and make player reset (pinhole)
on next start the player works as before, but you have a secure backup on pc