My First OS was a Custom TI Business Machine from 1985 that was Running TI-DOS, Unfortunately it was not MS-DOS Compatible.

Windows 98 SE.

Im probably the youngest user here.
My first OS was windows xp.
I think i started using it when i was 7.

Windows 95.

Windows 98 (From 1999 until 2005)...
I will never forget!

1995: System 7.1 on a Mac LC 520 my first computer, and first OS I used
1999: Windows 95 on Compaq P1/133 machines at school - crashed all the time! Yucks!

around 2004: WinXP SP1?

MS-DOS 4.

Windows 2000 Professional. I was only 2 back then. Good times.

EDIT: The only 'game' I ever knew back then was something called 'Run'

Still put it to good use for a number of times after XP became the best-est. Now it runs Windows XP at my grandpa's house.

Windows 95

Either DOS or 3.1, too long ago to remember

Mine was Windows 95.

Windows 98 I remember my favorite wallpaper on it

If I could remember, my mom used to take me to a playing center; they had a room where there was computers with Windows 98 and kids would get on them and play educational games such as Bailey's Bookhouse (old edition, not by Riverdeep).

GOD memories.

MS-DOS 5 on my pa's AT clone. I was three and we played text-based donkey kong.

Windows 98 and I play Microsoft My Personal Tutor for the first time (I think).

It was IBM OS/2 in 1990 something tried it in kindergarden

MS-DOS 3. That was on a VM. On real............ Windows 2000

MS-DOS 3.0 on IBM-compatible AT PC in 1992

Topic: "What was the first Operating System you ever used?"

If you used MS-DOS via a virtual machine then it is not the first operating system you ever used.

Hi, the first OS: MS-DOS 6.22 spanish + Windows 3.11 spanish, the oldest, some older version in english of MS-DOS on a PC-XT.

I started from Windows 98 in 2002-2003 and we installed XP in 2003. In 2010, we started to use Windows 7.

Windows Me on a 1998 Toshiba Satellite 330CDT laptop in 2003/2004

First I Used Windows 98 SE on a Toshiba laptop (2002 / 2003 Model)

That was Windows 98 on Pentium MMX, in 2004.