I use Windows Vista when I was yong on my Mom's computer (Acer Aspire 5610Z). Its running Windows XP now cause I don't know why I can't reinstall Windows Vista so the best choice is Windows XP.
Mine was Windows 2.11. Which was nothing but a file system. I used DOS before that. Someone told me about Windows on a computer. My first thought was why would I need a window on my computer. For I had never heard of a computer type of Windows.
I can't believe all of you are really this young. That surprises me. I'm only 50, and I still remember buying my first Radio Shack PC that used a cassette tape for storage. That was '82. Then I bought a PC Colt made by Commodore that ran Windows 286. Before that, I was testing different flavors of mouse driven OSes by Commodore and HP.