I am trying to connect to a new Windows Server 2008 R2 machine via RDP from a Server 2003 machine. I have (and would like to keep) enabled the requirement for NLA (Network Level Authentication) which is provided in RDP client 6.1. Unfortunately, RDP 6.1 doesn't seem to be available for Server 2003. Is there a way to do so without totally disabling NLA on the 2008 box?
As far as I know, NLA is not supported on Server 2k3 clients.
If you want, you can disable NLA by running tsconfig.msc on your 2008 R2 server, and deselecting the "Allow connection only from computers running Remote Desktop with Network Level Authentication" option under the RDP service.