Your player might hang up. Use a pen tip or other sharp object to insert the RESET hole gently on the side of the player and connect it again to your PC.

If it is still not recognized, your player may be at fault. Try the Philips Songbird software.
 
NOTE: Contents will be removed by using the repair function.

1. Install the Philips Songbird software and run it with your player connected to your PC. You can download it under the Software & drivers section.
2. Click on Tools --> Repair my Philips Device in Philips Songbird software, press and hold the corresponding recovery key on the player when connecting it to your PC. 
    
       
    
3. Follow the PC screen to recover your player.

Note: Make sure your PC is connected to the internet.

You can find the recovery key on your player from the below table.