Most Adobe software is what is called Desktop Software, meaning that it is designed to run from the Desktop, and not from a network, or similar. They are seldom designed to run with other "rights."
I dont run Win7, but I do run Vista-64, and I can attest to the fact that the Windows Security framework is a dark hole that is difficult for most to navigate thru and completely understand.
One can assume that with Win7, it's still a grey area that needs an official decoder ring for even the simple tasks.
I always install PE from the Admin Login and just give the rights to any User Account on the system.
With this approach I've never run into the situation where it must be Run as an Administrator.
If I'm not mistaken, PE may even require an Install from the Admin Login (I can't verify cause it's been so long that I've done the Install, that I don't remember).
The bottom line is if a particular Windows Object, PE in this case, is Owned by a particular Group or User, depending on it's Permissions and/or Access Rights will determine who can Run, Execute, or Modify that Object.
And unless your a Security maven, this could get real ugly, real fast (and you can screw up your System in a heartbeat if you don't know what your doing in this area).
Now you see why I install and Run it under the Admin Login and call it a day...
Where the Administrator rights gets ugly is in an academic situation, or a corporate situation. There is reticence by IT to allow students, or workers, to have that level of privilege. Especially in academia, this can be a major concern. Over the years, I have filed several Feature Requests, that Adobe make it easy to run some of their programs in a lab/networked environment, though I am not a teacher. I see enough posts from teachers, who are up against this issue, and are looking for some way to use the Adobe products, with little to no luck.