So you've got a machine at another location that you need to be able to operate but, due to Mutphy's Law, you never enabled Remote Desktop (RD). And, again due to Murphy's Law, the local operator can't enable RD. What do you do?
Enable Remote Desktop remotely using the registry editor and Connect Network Registry option. This allows you to enable Remote Desktop. Then, reboot the machine and you're able to connect.
Here's a good writeup on how to do this: http://oreilly.com/windows/archive/server-hacks-remote-desktop.html.