Well, first of all, Windows doesn’t really have a “uid.”   It’s a Unix/Linux concept (mostly “from the olden dayes of yore” even there), that Perl dutifully tries to emulate.   More or less . . .

So, in the Windows world, you really do have to do it the Windows way, as others have shown you how to do.   It can be a pain for cross-platform coding, heh, but that’s not the apparent issue here.