Mp3 foler doesn't open

Hello
 My MP3 player already get recognized by my computer once to add files but not more then one time.
The problem is that I CANT add files to the MP 3 since its always charging and not open the MP3 folder to add files.
What should I do?
Wait for answer.

Are you using the connecting cable that came with the player? Other cables may be charge only & not for data.

Thank you got it!