Hi westin

Thanks for your help and pointing me to a good resource

Should work for workstations as well as servers.
You can not find the domain user name “John Allen” within local users account at PC (WS-A), therefore you won't be able to add him to get permission to access his workstation WS-A,,,,,,,forget about server I do not like to give him permission to RDP to the server.

I want to give him RDP to his workstation only (my case it is WS-A)

On (WS-A) PC , right-click 'My Computer' > Click 'Properties' > Click the 'Remote' tab > 'Select Remote Users' tab ,,,,,I can not find the username "John Allen" because this account is not created locally it is a domain user account,,,,means you can not find his name to add him.