Hi, do we have any idea why the command hugo server can’t be called from cmd, windows powershell or any other terminal of windows (just like python can be called from anywhere) ?
Is hugo server required to create a website ? (i only wish to “build” from markdown to theme / optimized html/css)
I think those two have some quirks with text encoding and how they handle certain commands, hence the original issue by OP. When I used Windows, I found Git Bash more intuitive to use than tinkering with Powershell or Windows Powershell
Welcome to the Forum:
first a note: do not post new issues to yers old topics → please open a new one see Requesting Help
you state two problems:
execution from everywhere depends on your PATH setting. Add the location of your hugo.exe to the PATH environment variable and it can be started from anywhere.
p.s. There is no restriction for executing hugo on that. all shells work fine. BUT the shells behave different in some cases (f.e. file creation and encoding as @kijana mentioned). The Quickstart gives a guaranteed to work setup.
hugo is not a markdown file to html file converter. It’s designed to generate websites (SSG). and you have to tell hugo how the final result HTML should look like. If you don’t tell it, you’ll get your input back 
the technical minimal requirement is:
to get some output (md → html) additionally
If you do not use additional config settings or command line arguments, these are expected in a special directory structure
if you want something like a markdown converter, you could tweak hugo with a custom setup/config to behave like that. Maybe you’ll need to wrap that up in a script.
but details here depend on your usecase: