Why are sngs doubled on my s/d card?

[Windows Central Question]

songs doubled on my s/d card

I have a speaker box and when I plug the usb to my hard drive it starts downloading songs from my WMP and so I have duplicates and triplicates on my s/d card. How do stop it from downloading songs on my s/d card when I plug it in and how do I delete duplicates on my s/d card. Thanks