Or this can also happen: Note: Before following these solutions, it is essential that you back up your data and make a copy of your registry beforehand. Make sure there are no ongoing tasks on both the computer before carrying on.
Solution 1: Disabling NLA using Properties
Network Level Authentication is good. It provides extra security and helps you, as a network administrator control who can log into which system by just checking one single box. If you choose this, make sure that your RDP client has been updated and the target is domain authenticated. You should also be able to see a domain controller. We will go through the Remote Desktop Setting route and keep things simple at the start. If this doesn’t work, we have also covered other solutions after this one.
Solution 2: Disabling NLA using Registry
This method also works if you are unable to execute the first one because of some reason. However, do note that this will require you to restart your computer completely and may mean some downtime if you have a production server running. Make sure you save all your work and commit if anything is still left in the staging environment.
HKLM >SYSTEM > CurrentControlSet > Control >Terminal Server > WinStations > RDP-Tcp
Solution 3: Disabling using PowerShell
One of my favorite methods to disable NLA without getting into much specifics is disabling it using the PowerShell command remotely. PowerShell allows you to tap into the remote computer and after targeting the machine, we can execute the commands to disable the NLA. Here the “Target-Machine-Name” is the name of the machine you are targeting.
In the example above, the name of the server is “member-server”.
Solution 4: Using Group Policy Editor
Another way to disable the NLA is using the group policy editor. This is useful if you are blanket disabling. Do note that Group Policy Editor is a powerful tool and changing values which you have no idea of can render your computer useless. Make sure you backup all the values before proceeding. Computer Configuration > Administrative Templates > Windows Components > Remote Desktop Services > Remote Desktop Session Host > Security
Note: If even after all these steps you are unable to connect, you can try removing the machine from your domain and then reading it. This will reinitialize all the configurations and get it right for you.
Fix: An Authentication Error has occurred (Remote Desktop)Fix: Remote Desktop can’t Connect to the Remote Computer for one of these…Fix: This Computer Can’t Connect to the Remote ComputerHow to Fix the VAC Authentication Error
