Hi Georges,
- Have you tried turning off Firewall on both the computers?
- Have you started facing this issue recently?
Also, if you have any other third-party security program installed on the PCs then, temporarily disable them and check the issue.
**Important:**Antivirus software can help protect your computer against viruses and other security threats. In most cases, you shouldn't disable your antivirus software. If you have to temporarily disable it to install other software, you should re-enable it as soon as you're done. If you're connected to the Internet or a network while your antivirus software is disabled, your computer is vulnerable to attacks.
Refer to this article:
Why can’t I connect using Remote Desktop Connection?http://windows.microsoft.com/en-gb/windows7/why-can-t-i-connect-using-remote-desktop-connection
If that does not help, I would suggest you to post your query in the TechNet forum.
http://social.technet.microsoft.com/Forums/en-us/w7itpronetworking/threads
Hope this helps.
