Upgrade? That's when you find out your older, not ancient hardware can't run Win8. Time to get a new computer, which comes with Win preloaded. Cheap Dell for me.
It's easier anyway, and seems like upgrades always bring up all manner of cryptic (utterly baffling) messages that I'm happier to never see. Can't imagine why Microsoft never seems able to make things clear.
A new processor always means a big jump in performance, however satisfactory your old computer was before Microsoft obsoleted it. And doesn't your old hard drive really have too many miles on it? New box fixes this too. Just network old and new computers and copy files across. Software apps have to be reloaded, but again, wasn't it time for that anyway, and maybe some changes, now that you have to do it anyway?