J. P. Gilliver (John) wrote:

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).

The ancient version of DownloadHelper that I use with my Firefox 27
still worked several times today! (FF27 itself won't play the YouTube
pages, but load them into it, and DLH still works. OK, sometimes I have
to click "Next up" then the back button.) I'm on W7 (32 bit), but I'm
pretty sure those two are the same as I was using under XP.

I also endorse the recommendation of youtube-dl (with the "-" in its
name). OK, it's a command-line utility, with lots of fancy parameters,
but you can (and I usually do) use it without any (other than the URL of
the page containing the video, obviously). [And despite its name, it
works on almost any page with a video on it, not just YouTube's ones.]

youtube downloader still works!