I am tired of old applications behaving strangely because they cannot write to the "Program Files" directory. I don't want to have to manually set them to run as administrator, and I am not particularly concerned about security--in addition to trusting the applications I run, I only ever boot into Windows to run games (so the partition doesn't contain any valuable data), and I usually end up reinstalling Windows every couple of months anyway.
How can I make Program Files and Program Files (x86) into normal directories (from a permissions perspective) that every application is able to write to, regardless of permissions?
I happen to be running Windows 10 at the moment, but ideally I'd like to know how to do this on 8/7/Vista as well, for future reference.
Edit: I should note that I happen to be using an enterprise edition of Windows 10, so I can modify group policies or whatever else if need be.