First operating system was DOS 4 or 5, I think. On big 5.25” floppy disks on an 8088. Unless we’re counting whatever was running on a commodore vic20.

My first Linux distribution was Red hat Linux, somewhere around 1997, 1998 and I had a really tough time getting it installed.

I also once had a trial version of os/2 warp. Which was fun but pointless.