Symptom:
When trying to use RDP to a Windows Server 2008 machine, the following error message appears:
An authentication error has occurred. The Local Security Authority cannot be contacted. Remote computer: xxxxxxxx
Problem:
The security setting is too high to allow the account to log in.
Solution:
Lower Remote Desktop Security - On the terminal services server, go to Start, right click Computer, click on Advanced System Settings -> Remote Tab -> Allow connections from computers running any version of remote desktop (less secure).