private static void PinUnpin(string filePath, bool pin)
{
if (!File.Exists(filePath)) throw new FileNotFoundException(filePath);
 
// create the shell application object
dynamic shellApplication = Activator.CreateInstance(Type.GetTypeFromProgID( _
  "Shell.Application"));
 
string path = Path.GetDirectoryName(filePath);
string fileName = Path.GetFileName(filePath);
 
dynamic directory = shellApplication.NameSpace(path);
dynamic link = directory.ParseName(fileName);
 
dynamic verbs = link.Verbs();
for (int i = 0; i < verbs.Count(); i++)
{
dynamic verb = verbs.Item(i);
string verbName = verb.Name.Replace(@"&", string.Empty).ToLower();
 
if ((pin && verbName.Equals("pin to taskbar"))
|| (!pin && verbName.Equals("unpin from taskbar"))
)
{
verb.DoIt();
}
}
 
shellApplication = null;
}

 Private Shared Sub PinUnpin(ByVal filePath As String, ByVal pin As Boolean)
        If Not File.Exists(filePath) Then
            Throw New FileNotFoundException(filePath)
        End If
 
        ' erstelle ein shell object
        Dim shellApplication As Shell = Activator.CreateInstance( _
          Type.GetTypeFromProgID("Shell.Application"))
 
        Dim path1 As String = Path.GetDirectoryName(filePath) ' ist das 
        ' verzeichnis
        Dim fileName As String = Path.GetFileName(filePath) ' ist der Dateiname
 
        Dim directory As Folder = shellApplication.[NameSpace](path1)
        Dim link As FolderItem = directory.ParseName(fileName)
 
        Dim verbs As Object = link.Verbs()
        For i As Integer = 0 To verbs.Count() - 1
            Dim verb As FolderItem = verbs.Item(i)
            Dim verbName As String = verb.Name.Replace("&", _
              String.Empty).ToLower()
 
            If (pin AndAlso verbName.Equals("pin to taskbar")) OrElse (Not pin _
              AndAlso verbName.Equals("unpin from taskbar")) Then
                verb.DoIt()
            End If
        Next
 
        shellApplication = Nothing
    End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles Button1.Click
        PinUnpin("C:\W.exe", True)
    End Sub

Dim verb As FolderItem = verbs.Item(i)

Nicht implementiert (Ausnahme von HRESULT: 0x80004001 (E_NOTIMPL))