Windows XP, but it was during its ending phase, so I think it really was Vista. My first Linux distro was Kali Linux because I wanted to be a cool hacker when I was a kid. I never got too much into it then, though. I then found Ubuntu, and strangely enough, I switched to Trisquel, which wasn't too bad. I decided to go all the way and buy a T400 with Libreboot/Trisquel when I was about 15 years old and used that as my second computer for about two years. I learned how to start installing Libreboot myself. It was a really fun experience (not really, there was a lot of quitting and crying), but it taught me more about GNU and the entire philosophy. I started to learn more about GNU and RMS when I was 18. Now I'm 20 and use Arch. The end.