Thanks for the feedback davies.
I'm not sure that --force is really an unknown option. However, with perl-5.30.0, use of --force should no longer be needed.

I think the attempt to remove C:\Users\Administrator\.ppm/Image-Magick_-5188 is just a post-installation cleanup whose failure should not affect the I::M functionality.
I've come across that problem before, and never really worked out the mechanism by which permission is denied.
You can probably delete that directory manually if it actually exists && you want to get rid of it.

Annoyingly I'm not even able to successfully use ppm here, owing to some mysterious http access restrictions - so I can't test things out myself.

Cheers,
Rob