I have put the map in that map folder and still not working. I also have windows XP. I downloaded the map to the proper folder, I used the wizard to unzip the folder and transferred all parts of the file to the maps folder. I then started the game and the new map is not listed on the directory or the tab marked custom maps...
When you open the motherlode map with rar or zip you must extract whole folder ''The_motherlode'' into maps directory. BUT watch out Extract folder not RAR.
Well, I've already given as much help as I can. Just some general information on how to install maps:
-Drop it in the right folder -Make sure all the tga filenames are the same as the folder in which it is put in -Make sure there is a .map file, a map.xml, and an overrides.xml file -Make sure that the filenames are the same as the folder it is put in (the two tga files, and the map file)