Link: http://blog.ryantadams.com/2010/07/20/fix-remote-desktop-error-the-remote-computer-disconnected-the-session-because-of-an-error-in-the-licensing-protocol/

Steps for Windows XP/Vista/7

Log in as an Administrator.

Download this file to your desktop.

Double-click on the RDP_Fix.reg file you just downloaded to run it.

Respond in the affirmative to all prompts.

You will get a confirmation that the data was imported successfully.

Reboot your computer.

Start Remote Desktop. If you are using Windows Vista/7, you will need to right-click on the Remote Desktop shortcut and select “Run as Administrator”