Just struggled a little on a new install on Windows as well. The module I copied in couldn't be found. The problem turned out to be quite simple, but I figured it's worth mentioning in case someone else runs into it.

I copied the module into C:\Program Files (x86)\Odoo 11.0\server\addons. At first sight I thought this directory was specified in addons_path in odoo.conf, but on closer inspection that turned out not to be the case. The directory that is there by default is server\odoo\addons. By adding server\addons the module could be found.

addons_path = C:\Program Files (x86)\Odoo 11.0\server\odoo\addons,C:\Program Files (x86)\Odoo 11.0\server\addons

A thought for the OP: if the module is found but the install does not complete then probably an error occurred during installation. You can check odoo.log (in the server folder) for error messages and post them here or contact the author of the module with that information.

There is no difference for the installation of apps concerning local or remote/public servers. Cancel the installation of modules, which did not complete installation. Copy the modules to the correct paths (the paths you have configured in the Odoo configuration file) and ensure proper file and directory permissions. Then restart Odoo and update the module list. Try to install the modules again.

No joy on this. Directory structure has changed. Openerp sub-folder no longer exists. Path seems to be 

*/server/odoo/add-ons

according to the odoo conf file. Copied the extracted zip folders to those paths but all I get is a stuck partial installation of the two modules that I am trying to install. Installation can be initiated but never completes

:(