Solved! laptop connected by hdmi to tv but video only plays in a tiny window when maximised. Why?

[roundbase1]

when i connect my 4th gen i5 laptop to my tv using hdmi connection i can see the mirror image of the windows 10 interface but when i play video from my external hard drive i can only see it in a very small window on the tv....it wont maximise any larger than that. can anyone tell me how to get it to be full screen.

 

[hang-the-9]

What is the resolution of the video and what player are you using to play it? Does this happen to all videos? VLC Media Player is pretty good at adjusting options, use that and see if it runs better.