How to enter UMS (universal mass storage) mode (if using the H10 as an MTP device):

  1. Remove the battery for at least 3 seconds to reset the player.
  2. Replace the battery.
  3. Hold down the O button *and* power. Keep holding down the O button until you see *Emergency Connect* (if you are not using 2.10 firmware then it will probably say "UMS Mode entered").

Now the player should show up as a removable drive.