How do I import a module in PowerShell?

Run Import-Module -Name ModuleName for an installed module, or pass a path such as Import-Module -Name .\MyModule\MyModule.psm1. The parameters are in the Import-Module reference on Microsoft Learn .

Do I need Import-Module in PowerShell 7?

Not for modules in $env:PSModulePath, because they autoload when you first use a command. You still need it for modules stored elsewhere, for -Force reloads, and for options like -Prefix.

How do I reload a PowerShell module after changing it?

Run Import-Module again with -Force. Without -Force, PowerShell keeps the copy that's already loaded.

What's the difference between a .psm1 and a .psd1 file?

The .psm1 file holds the module's code. The .psd1 manifest describes it, including the version, author and exported commands, and points to the .psm1 as its root module.

What does Import-Module -UseWindowsPowerShell do?

In PowerShell 7 on Windows, it loads a Windows PowerShell 5.1 module in a background 5.1 process and proxies its commands through implicit remoting. The details are in the Windows PowerShell compatibility docs .

Import-Module in PowerShell: Load .psm1 and .psd1 Modules

Dana Reyes runs IT for Saguaro Family Clinics in Phoenix, and she keeps her laptop inventory scripts in one small module. Import-Module loads a PowerShell module into your current session, by name or by path:

Import-Module -Name .\InventoryTools

In this tutorial, I’ll build Dana’s InventoryTools module from scratch and use Import-Module in PowerShell to load it, reload it, trim it and unload it.

I ran every step in PowerShell 7.6 and Windows PowerShell 5.1. Where they differ, you’ll see both results.

This Tutorial Covers:

What the finished InventoryTools module does

Here’s the end result. One Import-Module line loads three commands that read a laptops.csv file stored next to the module:

Import-Module -Name .\InventoryTools
Get-InventoryValue
New-AssetTag -Number 105
Get-InventoryItem -AssignedTo 'Dana*' | Format-Table -Property Asset, AssignedTo, Model, CostUSD

Output:

Total laptop value: $5,387.49
PHX-0105

Asset    AssignedTo Model            CostUSD
-----    ---------- -----            -------
PHX-0103 Dana Reyes Surface Laptop 7 1499.99

Import-Module loading the InventoryTools module folder and running its commands in PowerShell 7 — Import-Module loads the folder, and the three exported commands work right away (PowerShell 7)

Windows PowerShell 5.1 printed the same lines. If you’ve never written a module, the steps below are a quick version of creating a PowerShell module from scratch.

Step 1: Build the InventoryTools script module (.psm1)

A script module is a plain text file with a .psm1 extension that holds PowerShell functions. Dana creates a folder named InventoryTools and saves this file in it as InventoryTools.psm1:

# InventoryTools.psm1 - laptop inventory helpers for the Phoenix office
function Read-InventoryFile {
    Import-Csv -Path (Join-Path -Path $PSScriptRoot -ChildPath 'laptops.csv')
}

function Get-InventoryItem {
    param([string]$AssignedTo = '*')
    Read-InventoryFile | Where-Object -Property AssignedTo -Like $AssignedTo
}

function Get-InventoryValue {
    $total = (Read-InventoryFile | Measure-Object -Property CostUSD -Sum).Sum
    'Total laptop value: ${0:N2}' -f $total
}

function New-AssetTag {
    param([Parameter(Mandatory)][int]$Number)
    'PHX-{0:D4}' -f $Number
}

Export-ModuleMember -Function Get-InventoryItem, Get-InventoryValue, New-AssetTag

Next to it, she saves the inventory as laptops.csv:

Asset,AssignedTo,Model,PurchaseDate,CostUSD
PHX-0101,Maria Lopez,Latitude 7450,2026-01-12,1349.00
PHX-0102,Tom Baker,ThinkPad T14,2026-02-03,1189.50
PHX-0103,Dana Reyes,Surface Laptop 7,2026-03-18,1499.99
PHX-0104,Alex Wilber,Latitude 7450,2026-06-22,1349.00

$PSScriptRoot is the module’s own folder, so the CSV is found no matter where you run from. Export-ModuleMember publishes three functions and keeps the Read-InventoryFile helper private.

Why doesn’t PowerShell find my module automatically?

Since PowerShell 3.0, installed modules load on their own the first time you use one of their commands. That’s module autoloading. Microsoft.PowerShell.Archive isn’t loaded in a new session, but asking for one of its commands loads it: