My external hard drive has changed to "Local disc (E:)?

Last night when I was putting a few movies on it, it started copying really slow. Then my computer was non responsive and it wouldn't let me safely remove it. Now when I plug it in it comes up at Loval Disc (E:) and says my device needs to be formatted before use, but when I format it it never works. It said "windows is unable to format.." It also says that it's not accessible. "The volume does not contain a recognized file system. Please make sure that all required file system drivers are loaded and that the volume is not corrupted" One time is said it may be "read only" Can I fix it? What's happened/happening? :( It's only about a week old.