"If you are watching DVDs on a screen you DO need a licence" I don't think that is actually correct, Dave.

Here is what the official TV licensing site says: ""Using television receiving equipment to receive or record broadcast television programmes without the correct licence is a criminal offence."

There have indeed been cases where people with functioning TV sets and aerials have unsuccessfully tried to persuade courts that they just used them to play pre-recorded TV tapes. It's conceivable that they might actually have been telling the truth, though I believe that the detecting equipment can actually tell the difference, and that evidence on these lines, casting doubt on the claim of the defendant, would have been given to the court in these cases.

But a laptop that wasn't plumbed in to any kind of TV signal, but which could play DVDs would be a different matter, and I am pretty certain there could be no question of a licence being legally necessary in such a case.