#Add new application pool
function Add-ApplicationPool([string] $AppPoolName)
{ 
    if (( .$env:SystemRoot\System32\inetsrv\appcmd.exe list apppool /Name:$AppPoolName ) -eq $null)
    {
      .$env:SystemRoot\System32\inetsrv\appcmd.exe add apppool /Name:$AppPoolName -managedRuntimeVersion:v4.0
    }
}