Computers normally do not turn themselves and begin online activities to which they can become infected. It takes a human, and a most suspicious one at that.
For one, you're overestimating the intelligence of the average human. Second, I never said anything about doing it on its own, it could be an advertisement, some random link someone throws up on a forum, whatever.
Regardless, considering no one knows exactly what anyone else on these forums does, it simply isn't a very good idea to recommend that someone run as admin all the time.
this much IS true: if you get infected, its MUCH less troublesome if you aren't running as an admin account. and, at least in windows 7/vista, having UAC around is one big deterrent to that.
Anyway, I'm done arguing this topic, feel free to keep arguing with nothinman. Like I said before, do whatever you want, but as for the OP, yes, under win7 you aren't running as admin unless the program asks for UAC access, to which your "superman" ticket then gets involved. If not, you run as your "clark kent" ticket, which is similar to running as a standard user.