The most important point that one should keep in mind when working with files and directories in .NET is the necessary permissions that are required for the user. It should be noted that the static methods of the File and the Directory classes require a security check for them to operate; this hampers the performance a bit. I would recommend using the FileInfo and the DirectoryInfo classes over the File and the DirectoryInfo classes if you have a lot of operations to perform on the files and the directories in your file system.