If files are located inside a folder in the KEY Ring Audio player, they cannot be played. Always put music files in the main directory of the player. * You may have formatted your KEY Ring Audio player with Windows Explorer. Reformat your KEY Ring Audio Player again with the KEY Ring formatter by going over the steps below. 1. Always make sure that the mode selector switch is in the DOWNLOAD/PLAYBACK position. 2. Connect the player to your PC. 3. At Start > Programs > Philips KEY Ring Wearable Audio Player, select FORMAT. The Philips formatter will launch automatically. (Please avoid using the Windows formatter to format the player, this may sometimes damage the player.) 4. Click START to format the player.