Not able to navigate folders/files in my MP3 player

The users manual says under File Navigator Mode: "1. In the MUSIC Mode, Press and Hold the “Menu” button to enter the Navigator" but this doesn't happen.
The first time I disconnected the player from my computer I did so without using the "Safely remove hardware" button and the system froze. After restarting I recopied the folder contents to the player as the troubleshooting section of the manual suggests, but it didn't help.