IIS Administration using PowerShell 2 and Modules on Windows 2008 R1

Unfortunately, it isn't possible to load the IIS provider as the same thing on both 2008 and 2008R2. On 2008 the IIS provider is provided as only a snapin, and on 2008R2 it is provided as only a module.

With a little bit of coding, you can actually determine which to use, and dynamically load the module or snapin in your script, depending on which is necessary. I took this code from http://forums.iis.net/t/1166784.aspx when I was having a similar problem.

$ModuleName = "WebAdministration"
$ModuleLoaded = $false
$LoadAsSnapin = $false

if ($PSVersionTable.PSVersion.Major -ge 2) {
    if ((Get-Module -ListAvailable | ForEach-Object {$_.Name}) -contains $ModuleName) {
        Import-Module $ModuleName
        if ((Get-Module | ForEach-Object {$_.Name}) -contains $ModuleName) {
            $ModuleLoaded = $true
        } else {
            $LoadAsSnapin = $true
        }
    } elseif ((Get-Module | ForEach-Object {$_.Name}) -contains $ModuleName) {
        $ModuleLoaded = $true
    } else {
        $LoadAsSnapin = $true
    }
} else {
    $LoadAsSnapin = $true
}

if ($LoadAsSnapin) {
    if ((Get-PSSnapin -Registered | ForEach-Object {$_.Name}) -contains $ModuleName) {
        Add-PSSnapin $ModuleName
        if ((Get-PSSnapin | ForEach-Object {$_.Name}) -contains $ModuleName) {
            $ModuleLoaded = $true
        }
    } elseif ((Get-PSSnapin | ForEach-Object {$_.Name}) -contains $ModuleName) {
        $ModuleLoaded = $true
    }
}

Before attempting to do anything with the IIS provider, check to ensure that $ModuleLoaded is true, and you should be good to go.