Lots of workshops, factories, university research labs, etc. still use old machinery that would be a huge waste of money to replace just because the computer that controls it runs Windows 95. In some cases it can't be replaced because the company that created the software, drivers, or IO cards is long gone.

the hardware and software licences for some of these systems can run into the millions too

I have a legitimate need to replicate systems that are sometimes very legacy for security research (apps that sit on top, rather than the os itself). Building stuff like a base Windows XP image is easy enough, but sometimes system updates are required - even stuff like iirc tls1.2 isn’t supported in IE6

I’ll also add: games and nostalgia.

Installing Acid Pro 6 requires Visual Studio Redistributable packages the Microsoft no longer has available.

At least, last I checked.

They have the C++ ones are available: https://learn.microsoft.com/en-us/cpp/windows/latest-support...

Historical preservation, retro computing, period-correct hardware setups.

The C++ redistributables are necessary for many programs and, for some reason, recent versions of Windows do not include them all.

There's a tool for blocking selected driver updates that still works on Windows 11. Very handy.

Out of curiosity, what's the name of this tool? Your comment made me wonder if it's possible to reimplement it as FOSS.

wushowhide.diagcab

Imagine you have a 2m$ spectroscope or offset printing machine running windows xp.

And it's not worth risking Windows 11 destroying it by slamming the irreplaceable robotic stuff into itself in such ways that NASA or NTSB would find fancy UI animations or virtualization based security culpable. You may insist that programs that control airplanes and nuclear reactors are supposed to be written in Rust + TypeScript on daily updated Linux installation that depends on AWS us-east-1, but they would insist it ain't stupid if it works.