Modules¶

Modules are packages of reusable PowerShell code — cmdlets, functions, aliases, variables, and providers — distributed as a single unit.

What is a Module?¶

A module is a self-contained package stored in a folder (or a single .psm1 file) that you can import into any session. PowerShell ships with dozens of built-in modules and thousands more are available from the PowerShell Gallery.

Module types¶

Type	File Extension	Description
Script module	`.psm1`	Functions and variables in a script file
Binary module	`.dll`	Compiled .NET assembly (C# cmdlets)
Manifest module	`.psd1`	Metadata file that describes the module
Dynamic module	(in memory)	Created with `New-Module`

Finding Modules¶

# List all modules installed on this machine
Get-Module -ListAvailable

# List modules currently loaded in the session
Get-Module

# Search the PowerShell Gallery
Find-Module -Name *azure*
Find-Module -Tag Security
Find-Module -Command Get-ADUser

Installing Modules¶

# Install from the PowerShell Gallery
Install-Module -Name Pester

# Install for the current user only (no admin required)
Install-Module -Name PSReadLine -Scope CurrentUser

# Install a specific version
Install-Module -Name Az -RequiredVersion 9.0.0

# Update an installed module
Update-Module -Name Pester

# Uninstall
Uninstall-Module -Name Pester

Trust the repository first

On the first install, you may be prompted to trust the PSGallery repository. You can pre-approve it:

Set-PSRepository -Name PSGallery -InstallationPolicy Trusted

Importing Modules¶

# Import by name (searches $env:PSModulePath)
Import-Module ActiveDirectory

# Import from a specific path
Import-Module C:\MyModules\MyTools.psm1

# Force reimport (useful during development)
Import-Module MyTools -Force

# Import and return the module object
$mod = Import-Module MyTools -PassThru

Auto-loading¶

PowerShell 3+ auto-imports modules the first time you use a cmdlet from them. Explicit Import-Module is only needed when: - The module is not on $env:PSModulePath - You need specific version control - You want to ensure all functions are loaded at script start

Module Discovery Path¶

$env:PSModulePath -split [IO.Path]::PathSeparator

Modules placed in any of these directories are auto-discoverable. For user-installed modules, PowerShell uses ~\Documents\PowerShell\Modules (PS 7) or ~\Documents\WindowsPowerShell\Modules (PS 5.1).

Creating Your Own Module¶

See Script Modules for a complete guide. The quick version:

Create a folder: MyModule\
Add functions in MyModule\MyModule.psm1
(Optional) Create MyModule\MyModule.psd1 manifest
Place the folder in a $env:PSModulePath directory
Import-Module MyModule

Minimal example¶

MyModule/MyModule.psm1

function Get-Greeting {
    param ([string]$Name)
    "Hello, $Name!"
}

function Get-Farewell {
    param ([string]$Name)
    "Goodbye, $Name!"
}

Export-ModuleMember -Function Get-Greeting, Get-Farewell

Useful Built-In Modules¶

Module	Purpose
`Microsoft.PowerShell.Management`	File system, services, processes, registry
`Microsoft.PowerShell.Utility`	Formatting, conversion, web requests
`Microsoft.PowerShell.Security`	Execution policy, certificates, credentials
`PSReadLine`	Command-line editing, syntax highlighting
`PackageManagement`	NuGet, Chocolatey, and other package sources
`PowerShellGet`	`Install-Module`, `Find-Module`, PSGallery
`CimCmdlets`	WMI/CIM queries
`NetTCPIP`	`Get-NetIPAddress`, `Test-NetConnection`
`ScheduledTasks`	`Get-ScheduledTask`, `Register-ScheduledTask`
`ActiveDirectory`	AD user, group, and computer management
`Az`	Azure cloud management
`AWS.Tools.*`	AWS management

Popular Community Modules¶

Module	Install	Purpose
`Pester`	`Install-Module Pester`	Testing framework
`PSScriptAnalyzer`	`Install-Module PSScriptAnalyzer`	Linter and best-practice analyzer
`ImportExcel`	`Install-Module ImportExcel`	Read/write Excel files without Excel
`dbatools`	`Install-Module dbatools`	SQL Server management
`oh-my-posh`	`winget install JanDeDobbeleer.OhMyPosh`	Shell prompt themes
`Terminal-Icons`	`Install-Module Terminal-Icons`	File icons in terminal
`PSFzf`	`Install-Module PSFzf`	Fuzzy-finder integration