[the7thson]

Sure, RDP is just Remote Desktop.
On Windows XP/Vista/7 etc you basically go to your Start Meny then My Computer (or equivalent), right lick and then Properties. Now Find System Properties/Remote tab and make sure that whatever is in there is checked. It should read something like "Allow remote computers to control this computer" or "Allow remote assistance in to this computer" etc. I don't remember the exact text but you'll know it as soon as you see it.

If you have Vista/7 (probably won't work on XP), just go to control panel, then type "remote desktop" in the search bar on the top right and it should come up.

If this fails or you're using an OS that I haven't mentioned, then just Google "how to allow remote desktop" for your OS.

Hope this helps!