Windows 2008 Terminal Services Network Level Authentication

You can change the Network Level Authentication configuration from ;

Server Manager -->Terminal services -->Terminal Services Configuration






Double Click to RDP-Tcp Connection





you can enable or disable network level configuration by checking or unchecking "Allow connections only from computers running Remote Desktop with Network Level Authentication check box is selected and is dimmed, the Require user authentication for remote connections by using Network Level Authentication" checkbox .

To use Network Level Authentication,
you need to meet all of the following requirements:

On the client computer, be using at least Remote Desktop Connection 6.0.
On the client computer, be using an operating system, such as Windows Vista, that supports the Credential Security Support Provider (CredSSP) protocol.
On the terminal server, be using Windows Server 2008.