Define modules in PowerShell

  • 5 minutes

Modules are groups of related PowerShell capabilities that are bundled together into a single unit. For the purposes of this class, you can think of them as containers hosting multiple cmdlets. Modules help with organizing cmdlets into distributable units. Microsoft and other software companies provide modules as part of the management tools for their applications and services.

You can check the list of available modules by running the following command:

Get-Module -ListAvailable

To use a module's cmdlets, the module must be loaded into the current PowerShell session. This typically takes place automatically but, depending on your configuration, might require that you load modules explicitly by running the Import-Module cmdlet. Some server products, such as Microsoft Exchange Server, provide a shortcut to what appears to be a dedicated management shell. However, this is really a normal PowerShell console session with application-specific modules already loaded.

Autoloading

In Windows PowerShell version 3.0 and newer, modules load automatically if you run a cmdlet that is part of that module. This works if the module that contains the cmdlet is in a folder under the module load paths. By default, these folders include %systemdir%\WindowsPowerShell\v1.0\Modules and %userprofiles%\Documents\WindowsPowerShell\Modules. The list of folders is stored in the $env:PSModulePath environment variable. When you explicitly import a module by name, PowerShell checks the locations referenced by that environment variable.

For PowerShell 7, the PSModulePath includes the following locations:

  • C:\Users\<user>\Documents\PowerShell\Modules
  • C:\Program Files\PowerShell\Modules
  • C:\Program Files\PowerShell\7\Modules
  • C:\Program Files\WindowsPowerShell\Modules
  • C:\WINDOWS\System32\WindowsPowerShell\v1.0\Modules

Note

When using Windows PowerShell, the path %systemdir%\WindowsPowerShell\v1.0\Modules is commonly referred to by using the combination of the $PSHome environment variable (which points to %systemdir%\WindowsPowerShell\v1.0) and the Modules path (that is, by using the $PSHome\Modules notation). For PowerShell 7.0, the $PSHome environment variable refers to C:\Program Files\PowerShell\7.