No folders in hard disk

hi actually my concern right now is i am not able to see any folders in my hard disk,i actually gave it to my cousin yesterday but today when i plugged it in to watch a movie,there was nothing except a shortcut icon,n that too is no more visible now. However,its showing the data is still there,the amount of space utilized can be seen and when i tired to scan it did gave the names of all the folders, it tried that command in cmd as well, attrib -h -r -s /s /d g:\*.* but that didn't work out, it says access denied system volume information,i don't know what to do please help me out its really important....