I have a Latitude C800. This morning we I turned it on the display came up very small with an 1.5" black border. Restarting has not helped. I use the laptop for teaching, and when projected through the projector the display is normal. Is reloading the display drivers the way to go?
Thanks for your help.

Right click on your Windows desktop and select properties. Go to settings tab and you'll notice two squares with 1 and 2. Try selecting one of them and see what happens

In settings, I only have one monitor showing with a window in the middle. Underneath it says Display: (Multiple Monitors) on Mobility M4

Is there more than one selection in the Display dropdown?

I see that you projected through an overhead. Try fiddling with the function keys - I think it is F4 or one that says LCD->CRT . Use FNC key and F4 together. It may think it is projecting to the projector

Thanks for you continued advice. Sorry I have been away for a bit. I tried what you said, but it didn't help, but it did get me thinking that I may have inadvertantly hit a wrong key when I was loading up the other day. hitting FNC F7 fioxed it. Should have know it would be simple, but I am not too computer savvy. Thanks again for your inadvertant help.