Holy crap there was literally a bug on my computer while I was posting this (alive one, not the PC one) . Anyway, my first one was i think Norton. On my uncle's computer. My parent's used Mcafe. They switched to Kaspersky while I'm still testing to find a good av. On my current PC (windows 8) I use avast! free edition.
I just started using my own personal computer since 2009, My first desktop was dell inspiron 560s, I was given with a pirated windows 7 ultimate OS, At that time i didnt know much about computing, So My First product was AVG, I dont remember whether it was AV or IS, but i was using it without knowledge!