Ian,

Has anyone else got the same problem

Probably.

Do I have to resort to a newly-acquired elderly machine running W10?

Have you already thought of using a Raspbery Pi for that job ? I've got
the 3B here, on which you can instal a program called 'YoutubeDL', which
seems to do the job quite nicely - next to the browser being able to view
Youtube movies directly (which is mainly what I use it for).

Regards,
Rudy Wieser

"Ian Jackson" wrote in message
...
All of my favourite (and not-so favourite) Youtube downloaders no longer
work on this XP machine.

Has anyone else got the same problem - or is it just me? Do I have to
resort to a newly-acquired elderly machine running W10? 4K Video
Downloader certainly does work on W10 - but later versions won't install
on XP, and older versions install but don't work).
--
Ian