I have a 32gb defective pen drive. In my computer, the capacity of the same was 31.2 gb. I used some tools and knew that it was USB2.0 flash disk having VID=1234 and PID=4321. Only one or two songs are played one time, when I tried to play the same again, there was a problem like "media changing". some datas restored for some time and when the pen drive inserted again, it could not be located. Some time formats of files automatically changed. Kindly suggest the way to fix the same.