I wanted to enabled remote desktop access for a domain security group so I search and followed the instruction here to get to the setting which was shown as "Not Defined" then I change the setting to add the security group, but it didn't work still. The same "..Allow Logon.." error message still occurs. So I decided to give up and revert the GPO settings to Not Defined.
I then tried to RDP with the Administrator account that had always worked, but to my horror it is not working anymore and the same "..Allow Logon.." error is shown.
I tried to gpupdate /force
but still nothing works. The document says by default for Windows Server 2008, the RDP access is enabled for Administrators, so I assume if Not Defined, my Administrator account should still log in after the GPO changes? What else do I need to do to reset the setting?