Just few months ago seen windows 95 error message on HSBC ATM.
I recently saw that running on special 16 channel DAT recorders used by the 999 service, recently as in "within the past five years". I believe they've been retired but kept around in case they need to recover tapes off them.
I kept my mouth ABSOLUTELY FUCKING SHUT about knowing my way round OS/2 Warp 4.
Except it would be nice if computers were as snappy as back then... so many layers of cruft that nothing really pops. I remember I used to just disable all the NT/2K animations and it felt so nice. I built a career on web apps, but most are just really poorly written it pisses me off.
You should try Haiku: https://www.haiku-os.org/
It's actually pretty usable these days, at least on Thinkpads and other "generic Intel chipset" machines.