I think that means something went wrong when the device was connected and the driver didn't get installed properly. The only thing I can think to do is to uninstall the driver and try again. Try running
USBDeview. This shows all current USB devices and any that have been connected in the past. If you can find the Kobo device in the list, right-click on it and select "Uninstall selected devices". Then plugin the Kobo and see what happens. If it still doesn't work, have a look at what USBView says about it.