cannot remove directory for C:\Users\USER\.ppm/Image-Magick-5488: Permission denied

That's kind of strange. Have you been running some commands as Administrator and others as a normal user? It'd be best to run all the installations under a single user.

So it looks like Magick is installed?? (I think!)

One way to check whether a module is installed is just perl -MModule::Name -e "" on the command line - however, this requires that the command line has the same environment variables set as the web server (such as PERL5LIB). They could be different if, for example, your web server is started via a batch file that sets an environment variable, or if you have environment variables configured in your Apache configuration (e.g. SetEnv directives) that only the CGI scripts run by the web server see.