powershell install module - manual and automatic

Manual

Where to install module? Use:
$env:PSModulePath
Create folder in one of directories, usually it is like: c:\Windows\System32\WindowsPowerShell\v1.0\Modules. This is legacy path, it can be located in different location - if this module will be used by more people - maybe You should consider a new place for modules. Place there downloaded files in some new directory, for example - if you downloaded PSPKI you have folders and structure like (only few folders in example, no files, but they are located inside): .\PSPKI-v.3.2.7.0 .\PSPKI-v.3.2.7.0\Client
.\PSPKI-v.3.2.7.0\Library
.\PSPKI-v.3.2.7.0\Server
.\PSPKI-v.3.2.7.0\Types
.\PSPKI-v.3.2.7.0\(main files)

So - create:
c:\Windows\System32\WindowsPowerShell\v1.0\Modules\PSPKI

and put there all files and folders from:
.\PSPKI-v.3.2.7.0

Automatic

If you have Powershell 5.0 or newer use: