I'm not 100% sure what you have already done?
Flash in Kiosk mode using standalone Flash will always scale to the monitor regardless of screen resolution.
If you are using HTML as the display method you need to make your tour scale and be 100% x 100% of the browser. This is an option when starting your tour build with Tourweaver.
Maybe if you can explain more about what you have already, we might be able to assist further.