Usb kingstone pen drive is not performing

Hello,
hi sir, this is rajiv i am having 8 gb kingstone pendrive.i want to copy the files to the pen drive
but it will copy and it will show the files but it will not read the files when i copy to the pen drive
after some the folder will show as like this ++++++++ +++++ ++++
+++++++ +++++ ++++ +++ +++ ++++++ ++++++++ +++++++++ +++++++++++ ++++
+++++++ ++++ ++++++ +++++++ ++++ +++++++++++++ +++++++++++++
it will show like this .i dont know what to do please send me the suggestion to me as
faster