Movies take up whole screen from lappy to monitor

[MetalMat]

When I plug my laptop into my monitor at home and attempt to play a movie file (avi, mpg, etc... ) it take up the whole screen on my external monitor. On the laptop screen itself it is normal. Anyone know a quick fix for this?

Another problem is that sometimes it will do an autorefresh and after it does that to the external screen it gets fuzzy.