Pendrive showing only 8MB

Hello,



respected sir,
my pandrive memory is 16GB. when I insert pandrive into computer then system show 8mb memory why and system changed into RAW from NTFS and not formatted at all. It is not opening at all, showing the "disk is not formatted". When I am triyng to format it in NTFS it is showing pendrive cannot be formatted. I have also tried HP USB disk storage format tool 2.06 but it still not working in any format NTFS, FAT or FAT32.
Please helpme to overcome this problem.