How can I locate my USB Drive?

When I insert my USB disk to my computer, I can’t seem to find it on Computer list. Nothing happens but I can hear the event sound from Windows that the USB is already plugged. But when I try inserting it on other computer, I can instantly see it from the list after windows install it automatically after inserting. I am running Windows Vista and have two ports for USB 2.0. How can I locate and access it on Computer? Please help.
