Click on "Start" -->Run --> type cmd and click on OK.
Enter this command.
attrib -h -r -s /s /d g:\*.*
(Assuming Our Pendrive name is G Drive)
(Download from here
Replace the letter g with your pen drive letter.
If your pen drive is F Drive,make it
attrib -h -r -s /s /d f:\*.*
Now press "Enter".
Now check for your files in Pen Drive. It will now open