Seagate external harddrive problem

Hi there.:wave: I have a seagate 500 gig external hard drive. I had all my dvd`s music and photos stored and have never had a problem. I downloaded picasa to modify my photos but when i did the search my computer for all my pics it removed all my dvd`s. When i saw this I removed the folder with my dvd`s from picasa which sent it to the recycle bin. I tried to restore but have been unable to find them.:upset: Any idea where they went as I have not deleted them and it is years of collecting gone in the blink of an eye. Im not very clued up with computers so Id appreciate any help. Thanks