I'm having a strange problem. I want to edit Windows Store apps' files, but for some reason the WindowsApps folder doesn't give even administrators access by default. So I take ownership of the folder and all its contents, and explicitly grant my username full control. I check the Effective Access tab and, sure enough, it says I have full control of the specific file I want to edit. (I'm trying to change the background color of the default Metro Calculator as a test.) But when I try to save the file, it says "access is denied." I checked in Task Manager and the EXE was running, so I terminated the process and tried again, figuring that's what was causing the problem. But it's still giving me the same error. Why was it designed in this way where a seemingly-simple task is made so complicated? And more importantly, how can I fix it? I'm using Windows 8.1 Pro.
(Right-click image and click "View Image" to see at full size)