HelperFunctions/Install-IiServer.ps1

<#
 .Synopsis
  Install Internet Information Server
 .Description
  Determines, if Internet Information Server is already installed and if not, it installs it
 .Example
  Install-IiServer
#>

function Install-IiServer {
    $isServer = $false

    try {
        Get-Command Get-WindowsFeature | Out-Null
        $isServer = $true
    }
    catch {
        $isServer = $false
    }

    if ($isServer) {
        if ((Get-WindowsFeature Web-Server).InstallState -ne "Installed") {
            Install-windowsFeature -Name Web-Server -IncludeManagementTools
        }
    }
    else {
        if ((Get-WindowsOptionalFeature -FeatureName IIS-WebServerRole -Online) -ne "Enabled") {
            Enable-WindowsOptionalFeature -Online -FeatureName IIS-WebServerRole
        }
    }
} Export-ModuleMember Install-IiServer