I have windows XP SP2 on one back zero updates.
I have Windows 7sp1 on 4 boxes only two has updates.
I have 2 VM's with 7sp1 and no updates. 1 XUbuntu VM but it gets updates as needed.
I have Windows 8.1 on one and it gets updates.. or use to.
I don't run AV on any of them and none of them have security problems because I dont use IE... I dont use JAVA.. not script but JAVA and I dont use Flash and I know what I am doing.
I have been infected.. yes.. several times in the past.. then I reload and problem fixed.
The only security I am worried about is out there on the Internet, My email's Steam, origin, my Bank.. shit like that.