No. The xorg.conf file just controls how X uses your hardware. This is a security issue. I believe that the file in play in ~/.Xauthority but I'm not sure.
Just open up the control panel to configure your desktop and find the applet to share your desktop with other sessions.
Or use the xhost utility to add permission for the remote host to create a display on your desktop. Here is an example for a remote host with address 192.168.55.66.
Also ensure that your firewall is set to allow remote X sessions to connect.
Here is more information.