most of people have problems with flash disk with deferent problem in frimware and hardware so the question is how do i know the kind of my problem?
if you have one of this problem  eg: write prtected or in general cant formated this problem in frimware of this disk so we can solve this problem by downloading a frimware app . all what you need to do is download chip genuis in the link : chip genuis
that give you the vid and pid of the flash disk that help u to search the right frimware to yours
how we can search using vid and pid ?
first thing go to this big site of frimware : http://flashboot.ru/iflash/

put your vid and pid below and then search 

try the utils that are the same capacity of your flash disk 

for eg i have a flash disk "adata" i have problem with it 

vid=058f pid=9380

so i will go to flash boot site and search 

the same vid and pid and flash vendor and capacity so all what gotta do is to search the utils in google and download it

the hardware problem in the next tech thanks for your time