do your tv specifications say that your television can play video clips?
software/hardware is required in order for a device to recognize file types and be able to convert them into an image on the screen. if you cannot access the files or display anything on screen the tv most likely doesnt support said file types.
if you are already getting video feed on screen but your problem is that it is not filling the whole screen are you sure that the video is of the same resolution as the monitor? you could fill the screen (but lose quality) by using the tvs zoom/fit commands.
if you cannot access the files from your tv then what about another input device? can your dvd player, other device access movie files on a usb memory stick and play them?