Lynda, UAC is a nuisance for users who don't understand it and even if you put in 5-foot-high letters "you need to run as administrator" still you will get calls saying your product is broken when somebody installs without enough rights to register runtimes or dlls.
My advice is to use inno install whose scripts make it very easy to require administrator escalation. If the user can't or won't agree to administrator rights, the installer won't do a part install to cause a support headache for you.
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1
