Likely, GTop is not installed on your machine, which is little surprising, because libgtop is a library out of the Gnome project which only exists for Unix, or maybe even only for Linux.

Depending on what you want to do, maybe Win32::Process or Win32::Process::Info might be of help for you.

As an aside, your post was in reply to a completely unrelated post. Please read the Perlmonks FAQ and maybe some introductory node, like turnsteps home node.