Dude 1st check weither Your DAta cable is working ......then if its not cables mistake i would advice you to format the phone once then try again if you can't format(if data is importent)then put your phone in mass transfer mode and copy instead of media transfer mode....
just goto settings >> Storage then click the propertyt button..........even if it dosent work out then the problem is with your windows (PC) may be virus just put a fresh copy...........
