getFileNames(@"c:\windows");

using System.IO;
 
public static void getFileNames(string srcDir)
{
  string[] files = Directory.GetFiles(srcDir, "*.*");
  foreach(string s in files)
    Console.WriteLine(s);
 
  string[] dirs = Directory.GetDirectories(srcDir, "*.*");
  foreach(string s in files)
    getFileNames( s );
}