[AccessD] Run Access 2007 as Administrator

I'm trying to install an Add-In and am receiving a message saying that I do
not have enough permissions. How do I:

a) run Access as Administrator? and/or
b) give myself Administrator permissions? and/or
c) restart/login as Administrator?

In many situations, I have right-clicked and found the "Run as
Administrator" command on the menu. It's not there when I click on the
start menu and select Access. I'm stumped. Since I am the only user of this
computer, why am I not automatically the Administrator?

Is this a "feature" of  Windows 8.1?

-- 
Arthur