I've connected my computer via hdmi however when we play videos it only shows the background

Solution
Is the TV set as an extended desktop? Drag the window you want to see to it.
Check how it is positioned in your video control panel. It may not be set in a position that makes sense in your application.
MERGED QUESTION
Question from Harley1992tres : "I've connected my computer via hdmi however when we play videos it only shows the background"

Using Samsung tv as computer display for videos/films
 


 
The question is if the TV is the only attached display, or if you have a monitor attached to the PC as well. With more than one display the 1st one is primary and the desktop is extended to the others.