Help me to solve my panasonic SV-MP720 500MB

my music player have a syntax error, in the sense,,, my mp3 lost all the songs automatically and when i tried to add songs from my personnel computer,with the help of mp3 data usb cable,,,,,, my computer will restarts automatically........ i tried with the laptop aslo same result!!!!!!

plse give a solution to this problm,of my panasonic music player sv720v