"Down load a video on my TV" - Do you mean you want to capture the video as it is being broadcast? No chance normally.
Some TVs do have the facility to record on to a USB memory stick - find your TV's manual and read it.
By far the best bet - certainly for someone who doesn't appear to have a clue - would be to get a personal video recorder. If you want to remove the saved programme for use elsewhere, get one that records to DVD. You can then use the DVD in a computer and capture that way.
Alternatively you might be able to get the video via one o fthe TV catchup services but exactly how you would do that will depend a little on which TV catchup service you are using
X, July 2015
