I know that windows xp home doesn't have an RDC server. If you're running xp pro or server 2003, you can access the settings in the control panel, system information (or whatever it's called), and then the remote tab, check to turn on RDC.
I don't have a Windows machine at home, so I may be off on the names but RDC won't work without that turned on. After that it's a simple matter of connecting with the RDC client on your laptop.
Another option might be to run a VNC server on your desktop and a vnc viewer on your laptop.
It all depends on what you're running.
What are the Windows version of the wired and wireless machine? – hyperslug – 2009-12-09T01:01:55.923