Removing Remote Desktop Restriction

We have a user that is getting an error message whenever they try to use Remote Desktop from PC’s with Windows 2000 Professional. The error message is: This Operation has been cancelled due to restrictions in effect on this computer. Please contact your system administrator. Other users of this PC do not experience the error, and this user is getting the error on multiple PC’s.

I have researched this enough to find that it is probably a registry key, but cannot determine which one. Most references to this error message refer to restrictions on Internet Explorer, not Remote Desktop, and thus direct me to the wrong registry key(s).

Any assistance would be appreciated.

Tom