UAC is located under control panel, user accounts
Superfetch can be located by clicking start, type msconfig in the little box above it, hit enter. It runs under services - msconfig is good for turning stuff off in your startup (google updaters, java updaters etc).
Wurz
Edit :- if you want to turn superfetch off to see if it makes a difference, click start, right click on computer, manage, go into services, right click it and click on stop.