Is it possible to access the login windows screen through RDP?

Solution 1:

Yes.

On the server, you will have to allow RDP sessions with network level authentication disabled (which is in the control panel remote settings), and either your RDP client must be old enough to not support network level authentication (i. e. from WinXP or before) or you have to connect via a .rdp file that contains the option enablecredsspsupport:i:0.

Also some vulnerability scanners will try to connect with network level authentication disabled and take a screenshot of the login screen - which is useful to determine the OS edition, OS language, whether the machine is part of a domain, and (in some cases) some valid user names.

Solution 2:

Yes, you would disable “Network Level Authentication.”

If you are looking at the remote access settings on the host, you would enable the setting to “Allow connections from computers running any version of Remote Desktop.”

Then you may need to follow a guide like the following, to disable NLA on the client as well. http://blog.backslasher.net/using-remote-desktop-client-without-network-level-authentication.html

It’s considered less secure and should not be enabled on a publicly accessible host.