If you still get this problem with the disc in the drive, you might have to verify that the registry-entry is pointing to the correct drive. Not the brightest move to put the path to the data-drive in the registry, but there you go. I'm currently on a machine running only Linux, so I don't trust myself to navigate the registry for you, but search for 'datadrive' or 'Square Soft, Inc' (or only 'Square') and you should get there eventually. It'll be one of several keys in the right pane.