Installation and Update

You can install Pester using the built-in Install-Module command. The examples below will install Pester in your default installation scope depending on your PowerShell-version. You can control this using the -Scope <AllUsers/CurrentUser> parameter.

Windows 10 / Windows Server 2016 and later ships with Pester version 3.4.0. This built-in version cannot be updated using the simple Update-Module cmdlet. Instead you need to perform a side-by-side installation to get started with the latest version of Pester.

The built-in version is signed by Microsoft while newer versions are community-maintained and signed with a different certificate, causing Install-Module to sometimes throw a error requiring us to accept the new publisher certificate.

Run the command below to install the latest version:

# -Force to install side-by-side
# -SkipPublisherCheck to accept the newer certificate

Install-Module -Name Pester -Force -SkipPublisherCheck

For any subsequent updates it is enough to run:

Update-Module -Name Pester