Splash and ME startup screen has changed size

Recently I changed my display to connect my laptop to my
tv. Somehow, I changed the size of my 'Dell' splash
screen on startup from full screen to a 'small' size
splash ... and they same has happended to my ME splash
screen. I was hoping someone could let me know how to
return it to both original sizes. I have tried restore
but this did not work.

Thanks in advance.