Problem with WD My Book Essential Edition 2.0 500GB

I have an issue with accessing my wd my book essential edition 2.0 500gb. I am running windows vista ultimate 32 bit. When i try to access it with left clicking it from “My Computer” it does not respond. But when i right click>open i can access normally my hard disk. I would like to give me some advice on how to solve this “little” issue. Thank you for your time.