Error installing package 'dbi.ppd': Could not locate a PPM binary of 'dbi.ppd' for this platform

That's telling you that you downloaded the wrong zip. Try again.

I tried dbi.ppm, moved all the files to per\bin, copied them to the lib and site\lib directories... all to no avail.

Please don't do that. See A guide to installing modules (I don't have PPM, how can I install a package?).