oh i have one to. its not hard
1.u take ur usb adapter connect it to the comp.
2.turn on the the mp4
3.a window should pop up (if i doesnt go to start right click it go to explore and look for removable drive)
4.once u open it should be empty and just import ur songs.
5.for videos u might need to convert it. u can go to mympxplayer.com to download the software.
dude thats the samething as mines when i look for the removable disk thingy and i open it theres nothing in it not even a single folder. i tried importing a song in it but it wont accept it even tho its in mp4 format
the songs can be in mp3 format. just copy and paste it. when u open the removable disk folder there should be nothing in there maybe a few notepads in there but thats it, it should be empty. if nothing works its the actual hardware itself. the mp4 should work though. when buying fake mp4 u should check the back for fcc approval.