its not that simple as i found out, apparantly the ds won't read some files when they're in folders so try copy/paste the files out of the folders but what i did was first format your mini sd card ( u need a usb adapter or sd adapter ) that means wipe it clean and then u gotta download some software to make it work, I figured it out with the help of you tube, put in, set up r4 card and there is an ultimate beginners guide on there which worked for me, good luck x