Strange RDP / Remote Desktop problem

Question

I'll try to be as specific as I can be:

• Server is running SBS 2008 R2 (with all updates)
• Server is connected to the internet
• Server has 2 NIC's, one is disabled
• Server is running RDP Service (accessible directly from the internet, I know, not as secure as it should be)
• Computers A and B are on the same local net.
• Computers A and B are both Windows 7.
• Users X and Y are both admins on the server
• Computer A can connect as user X to the server with mstsc
• Computer A can connect as user Y to the server with mstsc
• Computer B can connect as user X to the server with mstsc
• Computer B CANNOT connect as user Y to the server with mstsc! Error that username/password is incorrect.

The last point is the problem, I get an authentication error. This used to work flawlessly for the last year. The server and desktops have been rebooted.

EDIT:

I tried:

• prefixing domain to the username
• prefixing the server computer name to the username
• change the password
• copy/paste the password from notepad to make sure it was correct

I find it very strange....

EDIT:

• The computers are not on the same subnet as the server. The server is at my hosting provider.
• All computers as all users can reach the web app that is running on the server.

Solution

I was having this exact same issue. All I did was log into the local administrator account via RDP, logged out, and all users were fixed.

The local administrator account did NOT have an active session after a server reboot. Very strange.

Comments

[Admin]

We had exactly same issue with service accounts we had just created in Windows 2008 R2 Enterprise Active Directory. All attempts to store password in KeePass or notepad and log in later failed. Only typing the password in from keyboard worked. Very frustrating. Our RDP client was on Windows 7 machine. I was thinking it might be some kind of unicode mismatch, and my partner is thinking maybe one of the RDP clients is out of date. Really scratching my head over this one.

[Falcon Momot]

Is AD involved?

[Slartibartfast]

I've had a strange experience similar to user75802 where I discovered that KeePass requires me to use ctrl-v to paste a password into the RemoteDesktop authentication box. In this case, what does the Security event log show for the successful and failed logins? It should include fail reasons for failures.

[John Landheer]

See my edit. The error message is in Dutch but it is exactly as if you have a invalid user/pass. No other info like an error code is given. Just "authentication failed". pw is correct, from another machine it does work.....