Not sure if I can help you from scratch since I haven't done this test in my environment (although I have read a lot about it), but the following will have to be done:
First, do you want to connect to his laptop to help him with something, in other words, do you want to connect to the laptop AND be able to see what he is doing on the screen so you can help him with something (called remote assistance in Microsoft terminology) OR do you want to connect to the laptop and run it as if you were sitting there (without his intervention)?
I've heard a lot of people use VNC for remote connection over a WAN, but I haven't tested that so I can't explain.
Assuming you will be using Windows XP and you want to connect to his laptop to achieve the first result (remote assistance), you will need to do the following (sorry, I can't provide you with step by step instructions right now since I'm on a linux machine, but i'll do my best from memory):
He will do the following:
1. Go to System properties, click the Remote tab, and check the box that reads "allow invitations to be sent from this computer." Then go to Windows Help and Support (found on the Start menu)
2. There will be a link there that says something like "remote assistance," or "request assistance"........click it and follow the on screen instructions. He will eventually be asked on how he wants to send the invitation and he will send it (i prefer to send it as a file [attachment on an email]).
3. If he has ICS or ICF setup on your computer, you will need to enable the remote assistance/remote connection service or port on the Windows Firewall (port 3389, but ICF has a simple check box that you work with to allow it). If he has a router in front of your computer, he will need to enable port forwarding for port 3389. That basically forwards Internet traffic (in this case, remote assistance packets) from the Internet (your computer, in this case) to the port on his computer.
At this point, his computer is ready to receive remote assistance
Your side
1. You will receive the file and you will double click on it. You may be prompted to enter a password (if he set it up like that). You will eventually connect and you will be able to chat with him and send files back and forth while connected.
If you want to establish a remote connection and feel as if you are working right on the computer (without his intervention), then the following will need to be done:
He will on his computer
1. Go to System Properties and click the Remote tab and check the box that reads "allow other to connect remotely to this machine" (something along those lines). He will click the button that reads something like "specify users" (the button that allows you to enter the usernames that can connect remotely to the computer.
2. He sets up the port forwardings on his side
You will on your computer
1. go to Start > Run, type mstsc and the window that pops up, type his IP address of his computer and you will be prompted for the credentials to the system.
2. You should connect
Again, the above is a from memory version of the directions on how to do it........for more detailed instructions, Microsoft, Google, and Windows help are your friends
