Computers, ehh? 6th grade graduation field trip, we went to Carnegie Melon museum in Pittsburgh. The highlight was being allowed inside the observation room, where we could watch people working on a real computer. The computer occupied a space at least 30 feet in depth, and 60 feet in length. A glass wall separated observers from the computer room. We watched people preparing punch cards, other people placing those cards into readers, other people performing one function or another. That computer was state of the art, and there was only one other computer like it in the state of Pennsylvania. We all got used punch cards to take home with us. Sorry, I don't remember any more details, have no idea what operating system it used, or how much electricity it used. I only remember that it was a HUMONGOUS thing, and that about 20 people were needed to keep it in operation.
That was 1968.
Later, in the Navy, I started learning a little more about computers. A buddy had one of those newfangled TRS-80 Radio Shack computers, which operated from a cassette tape - there were no floppy disks at the time. There were no disk operating systems (DOS) at the time, lol!
You mention the Windows operating systems - I had a Windows 1.something. Can't remember for sure if it was 1.0 or maybe 1.1 or something, but it was primitive. And, of course, those earliest Windows versions ran on DrDos. It wasn't until Win 3.1 that Microsoft introduced code to prevent Windows from running on non-Microsoft operating systems.