Gary, your machine is old, but if it is stable, then I say, stay with it.
When Norton no longer release updates, then it might be time to look at a new one. I would suggest you have, as a minimum, another 18 months or so.
Personally, I like XP & Win 7, not a fan of Win 8, but thats just me.
My laptop is running Win 7, and my pc for the CNC is running XP. When the XP machine dies, I will probably replace it with another one, still running XP. It doesn't do any automatic updates, has no anti-virus, but contains NO data of any use to anyone. It's even has a wireless connection. :eek:
Business applications are a totally different kettle of fish, and there is some push to get these machines updated.

