This example creates a folder and a subfolder on a computer. // Specify a “currently active folder” string activeDir = @”c:\testdir2″; //Create a new subfolder under the current active folder string filePath = System.IO.Path.Combine(activeDir, “mySubDir”); // Create the subfolder if (!System.IO.Directory.Exists(filePath)) { //Create directory System.IO.Directory.CreateDirectory(filePath); } For more info see: http://msdn.microsoft.com/en-us/library/as2f1fez.aspx