Public Sub RemoveUnusedApplicationPools()
        Dim manager As New ServerManager
        Dim AppPools As New List(Of String)
        ' fill the list with all pools
        For Each apppool As ApplicationPool In manager.ApplicationPools
            AppPools.Add(apppool.Name)
        Next
 
        ' if it's used remove from the total list
        For Each website As Site In manager.Sites
            For Each app As Application In website.Applications
                AppPools.Remove(app.ApplicationPoolName)
            Next
        Next
 
        ' remove the unused pools
        For Each unusedApplicationPool As String In AppPools
            Dim apppool As ApplicationPool = manager.ApplicationPools(unusedApplicationPool)
            manager.ApplicationPools.Remove(apppool)
        Next
 
        ' call the commitchanges method
        manager.CommitChanges()
        manager.Dispose()
    End Sub