No folder Access

Question

I want make a program with C# for scan a folder after the scan i want see how many files and folders in the selected rootfolder. But if i take a folder like C:\ or program files orso i get a access error, Like access denied for folder c:\$Recycle.Bin\S-1-5-18 when i want scan folder C:\ when i create a folder on my desktop with some files and folders then i get no error and works the program fine.

The code that i used is like this

public partial class MainWindow : Window
{

   System.Windows.Forms.OpenFileDialog ofd = new System.Windows.Forms.OpenFileDialog();
}

public MainWindow()
{
    InitializeComponent();
}

private void btnScan_Click(object sender, RoutedEventArgs e)
{    
    if (Directory.Exists(TbLocatie.Text))
    {
       // @"C:\Users\Alexander\Desktop\test"

        DirectoryInfo di = new DirectoryInfo(TbLocatie.Text);

        System.IO.FileInfo[] files = di.GetFiles("*.*", SearchOption.AllDirectories);
        int countfiles = files.Length;
        lblFiles.Content = countfiles;

        System.IO.DirectoryInfo[] bestanden = di.GetDirectories("*.*", SearchOption.AllDirectories);
        int countbestanden = bestanden.Length;
        lblBestanden.Content = countbestanden;     

        FileSystemInfo[] filelist = di.GetFileSystemInfos();
        FileInfo[] fileInfo;
        fileInfo = di.GetFiles("*", SearchOption.AllDirectories);
        FileSizeFormatProvider sizeconv = new FileSizeFormatProvider();
        long size = Convert.ToInt64(fileInfo.Length);

        // double sizeMB = Convert.ToDouble(lblGroote.Content);

        for (int i = 0; i < fileInfo.Length; i++)
        {
            size += fileInfo[i].Length;
            lblGroote.Content = size;
        }

    }
    else
    {
       System.Windows.MessageBox.Show("niet gevonden");
    }
}