Copy the content from your drive to another one and then format it. Check when formatting that you are creating a files system with the correct capacity. (Sometimes formatting tools don't automatically identify the capacity of the device properly.) When formatted copy your content back.
Not all formatters do the same thing. An HP tool called HPUSBDisk.exe seems to be able to restore a USB drive to the correct capacity when others can't.
Gary
January 2017
howtomendit.com for free repair help, information and advice.
