Have you tried pressing and holding it? That's the Android equivalent of a right-click on the mouse, and may bring up some options.
BTW I'm not clear what the "start up screen" is: to me that would be the splash screen when you boot the device, but that clearly won't have any icons on it. So do you mean the lock screen, your home screen, or something else? Knowing this would give us a better chance of working it out.