Uknown Files and Folders may cause my chinese mp3 player to not play songs

guys! please helpme! or my friend will kill me. my friend gave me his chinese mp3 because he wants me to put song into it. but after i finished putting songs, i test it but it wont play! i connect it again on the computer and one of the folder contains folders that has random names( look at this picture:http://www.flickr.com/photos/9505902@N04/4071126659/sizes/o/ please guys help me to make this mp3 work again and delete thos file cause i cant delete it! thx guys!