I don't think this is possible on Windows without administrator. It certainly shouldn't be, if it is.

But anyway, the fact that any userspace software can read all your personal files without any user confirmation as soon as you double-click on it is not a good thing, and as I said, all desktop operating systems are attempting to address this problem in some way, including Windows. I imagine the normalization of rootkit-style anticheat has become a pain point for the security team at Microsoft.