PC to TV problems

i have a problem watching movies on my tv through my pc. everything works fine i can see my windows desktop screen and whatever else on the tv until i start to play any sort of video file then that section appears blank on my tv but i can still see it on my pc. im connected through an s-video cable.can anyone help?

In most of the cases u need to install " generic TV” as a graphic card. If u use nvidia graphic card yo’ll probably need a software named “TVtool”.
good luck