the desired screen size is 1280 x 480 and my laptop is 1280 x 800. why won't it just stretch to fit?
Because your graphics card is saying it can't do it. You can't set a resolution unless your videocard - via your videocard drivers - says it can do it. Evidently, your drivers are saying "no thanks".
also for the project i am doing i need to use 2 screens (control panel settings with a second monitor)
I'm pretty sure B3D doesn't like two monitors. If you can set them up so that Windows sees them both together as one giant desktop, you might be able to create a single fullscreen display which fits over both, but the monitors would need to have the same vertical resolution, and even then you'd need a dose of luck, I think.