MS-DOS 5 or 6. I guess technically I used whatever Apple IIes had, first, but really I just loaded games from disk.

My desktop OS history:

1. Windows 98
2. Windows XP
3. Windows Vista
4. Windows 7
5. Ubuntu
6. Linux Mint
7. Antergos
8. Arch Linux
9. NixOS

I've used others, but not enough to warrant a place in the list above.

C64 -> MS-DOS 3 -> 4DOS -> Win 95 -> Win 2000 -> Debian -> Ubuntu -> chaotic smattering of various distros that changed almost weekly -> Mint -> Arch -> Manjaro -> MXLinux -> SteamOS (SteamDeck), Rasbian.

DOS and Windows 95. First linux distro was Ubuntu in the mid-2000s when I got a used netbook that I wasn't aware had linux instead of Windows on it.

Sinclair Basic on my ZX81 with 1k ram. My first personal linux distro was Redhat 5.2. I used VAXVMS at work.

Briefly some form of DOS on an Amstrad PC when I was very young, then Windows 95

My first Linux was a few years later with Mandrake IIRC, which I dual booted with Windows 98SE

Been running combinations of Linux and windows since then, with MacOS getting involved in the 2010's too

Knoppix 3.something

It was ages ago.

Windows 95, Knoppix and Mandrake Linux.

Hmmmm Amsdos on an early amstrad CPC machine

First I put real time on would have been the Atari TOS, man those machines where the biz at the time!!

Windows 3.11 and Kubuntu 6.06LTS (still have the CD!)

Windows 3.11

DOS s.u.s.e. 4.x or 5.x

Desktop: Windows XP

Linux: Probably Raspbian on a Pi 2 b

Tech has come a long way since then lol

My first OS was Apple OS and what the NCR's ran in 1978. My favorite game was snipes on Netware in 1986? My first OS distribution via retail box was windows 1.0. My first Linux distribution was FreeBSD 2.0 er wait.... My first Linux distribution was Debian 1.1 buzz on 3/5" floppies.

Comodore 64 os in the late 80's then msdos, win 3.1, etc. First Linux distro i believe was either slackware or debian.

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.

DOS/Win3.1 I was pretty young. It was far back enough that it was still common to find Apple II's in my grade-school classrooms off to the side for when we had downtime. I regret that I was just a little too young to experience the Commodore 64 craze.

First OS was C64's Commodore KERNAL/BASIC 2.0 GEOS, if that even counts as an OS, the next was Amiga 500's AmigaOS

First Linux distro was Fedora

Windows 1998 on a Pentium2. First linux distro was Ubuntu, uh....8.04 I think ? That was much later.

DOS -> win95 -> win98 -> debian (and i'm still here 24 years later...)

First OS was DOS (I think) on an Apple IIE at school. I think there were a few Commodore 64’s there as well. A couple years later we got our first home computer running Windows 95. Good times playing Doom, Jane’s Apache, an MS Flight Simulator.

My first personal computer was running Windows XP and I switched to Ubuntu sometime in 2004. Ran Ubuntu for the most part till a few months ago when I switched my desktop and laptop to NixOS.

Started self hosting services in 2012 and started with Ubuntu as base OS. Now though most of my servers are Proxmox with the VMs usually running Ubuntu LTS, though NixOS is starting to creep in there as well.

First social media post that's ever made me feel young! Earliest I remember was Windows 95, but I didn't do much besides play with MS Paint.

For Linux I started with Wubi to install Ubuntu 8.04 Hardy Heron. It installed Linux as a program in Windows and added some kind of hacky boot entry to boot into Ubuntu from your windows partition. Pretty cool, and I'm still pretty nostalgic for the GNOME 2 aesthetic with compiz effects from that time.

DOS - Win3.1 - Win95/98 - BeOS - Red Hat Linux - WinXP - Mac OS X - WinVista/7/8 - MacOS X - Win10 - Debian Linux (and staying with it).

MS DOS 2.11.

Windows 7 -> Windows 10 -> Kubuntu -> Linux Mint -> Nobara -> Pop!_OS -> OpenSUSE TumbleWeed -> EndeavourOS

First OS: DOS 4.something on dad's PCXT clone.

First Linux: Kurumin Linux

First OS: I think it was Windows 98. I have then gone through XP, Vista, 7 and staying at 10 for as long as i can.

First Linux distro: Ubuntu 10.04 or 10.10 don't remember clearly but it certainly was before GNOME 3 and in a VM. From then i have also run Fedora, Debian and most recently Linux Mint and Pop! OS in VMs as well. Maybe one day i finally set up a dual boot...

On my first PC it was DOS 2.0, but before that I had a Vic-20, then a Commodore 64.

My first OS was whatever ran on a Commodore 64. I guess the Commodore kernel and Basic?

My first distro was whatever version of Fedora was current in the fall of 2008. I'd gone to university that year and my laptop crapped out. Couldn't afford a legit Windows license at the time to replace it, and I'm pretty sure I just remembered that Red Hat was a thing and found Fedora that way. One thumb drive and 16 years later, still using linux, so I guess that was about the only good thing to come from my abortive first attempt at higher education.

Probably some version of DOS, I can't remember. First Linux distro was Fedora Core 4.

First os: technically the Wii's os and android

First Linux: Ubuntu 16.04 (I remember it like it was yesterday 🥲)

Zx spectrum --> msx-dos --> ms-dos --dr-dos --> win95 --> Suse (before it was bought by novell) --> win98 --> debian

Windows 98. Later the first Linux distro I tried was Mandrake Linux but I didn't really get into it until later with Crunchbang.

The first OS I recall using is Windows 7 (yes I’m young), and for Linux, I switched from Windows 11 to Linux Mint, which is what I use in the present day.

First OS windows 95 First linux distro ubuntu Currently manjaro, windows 11, macos

First OS, WinXP.

Later when win7 was discontinued, I kept windows 10 on my desktop and Ubuntu on my laptop. It wasnt until Valve started working on proton and most of the games I play became playable on Linux that I ditched windows entirely.

I distrohopped around for a while, but always found myself landing back on Ubuntu, so it's what I've stuck with to this day, although if anyone else asks me what distro they should get, I will usually recommend mint.

Well, this sets a new level of recent here judging by the comments.

Desktop OS: Linux Mint 20 MATE. Yep, that's right. I only got my first proper computer in 2020.
Thankfully, I had to install the OS myself, which was of course preceded by choosing an OS.
I had Windows 10 on that laptop for 2 days which served me to compare different OSs and burn the install DVD. I had no flash drives, and just dug out one old DVD-RW. OK, I'll be honest, hearing about Linux first I was searching for "just Linux", pure Linux, not derivatives. Oh well, GNU+Linux copypasta actually being helpful.

Alright, but why did I "have" to install an OS if I got it with Windows? It was used. I did reset it, but even though it was my first proper PC, I had no lack of paranoia. I thought that someone before me could have put spyware on that.
And I was right. Not the way I thought, but I was. That someone was Microsoft.

School: if it wasn’t a Macintosh Plus it was something like it. We were given very little time with it and had to go to a special computer room to use them so I don’t remember a lot of specifics about it, beyond the school tech guy having to painstakingly load each program we wanted to use manually from a floppy

Home: Windows 3.1. I don’t think we got the internet until Windows 95, though

Microsoft Extended BASIC