Hi Noir911,
Welcome.. Its great your getting folks to get connected!
Ok.. where to start..
If he has never had WinMX on his system or its uninstalled at this time the best course of action is to get the Install Version 1.9 from here:
https://www.winmxgroup.com/Make sure that the file is 1.3MB in size when the download is complete. Very important as we have had several folks not get the entire file the first few download attempts.
Next have him/her run this file and allow it to install for the XP operating system.
When the Installation gets to the point of testing the TCP and UDP connections, it will often fail. Its best to tell them to choose the configure manually option at this time.
This is the test procedure, stop this and choose to configure manually.
They will see this screen next, you need to leave these settings as they are here.
Here set the port to Listen on port 6699 by ticking the top option.
Here set the port to Send and Receive on port 6257 by choosing the top option.
Once this is completed they should be able to just sit back and let it connect.
As you know they should see the yellow flashing on the Networks page turn to Green at this point.
If they do not then have them reboot the computer at this time, and restart WinMX after this. Its best to allow it to connect as a secondary the first time they use it to be sure the connection itself works. If they use a primary this can fail to connect due to primary requirements
Let me know if they or anyone has any further questions..
Remember that they will need to allow those ports in any firewalls, and routers for WinMX to work properly.