My first Windows version to be used was
Windows 98. Oh man, the greatness! I was a little kid and I spent hours drawing with Paint (all I could do since I had no internet).
But the most memorable was for sure
Windows XP. That's where I developed my passion for technology. That's where I first knew
gaming and where I started learning about security, fixing computers and cleaning malware. That was when I first started doing antivirus testing (testing which one was better for my system) but of course in a horrible way, installing more than two antivirus at a time, making it unbootable. Oh, good memories. I owe XP so much!
I broke my PC so many times playing with antivirus and software, that my mom was so sick n' tired of paying a technician to fix it so she stopped doing it. That forced me to start looking for tutorials and be my own teacher on the subject, and that made me the nerd I am today!