My dad used to run a whole commercial bank on MS Office 4.0 and a 386. (A small one, but still!)
Small, medium and large colleges in the UK ran on Novell servers and 386 client machines with windows for workgroups and whatever Office they came with. I think the universities were using unixy minicomputers then though. Late 80s early 90s. Those 386 machines were built like tanks and survived the tender ministrations of hundreds of students (not to mention some of the staff).
I love this story where a C64 in Poland rans a Auto repair shop.
https://www.popularmechanics.com/technology/gadgets/a23139/c...