All the *.res files belong directly in the skins folder. You will have to go online for a bit to get the "skins.res" file. Remove that file from the "skins" folder. Go online. You will get a new "skins.res" folder which should allow you to access any of the skins you have installed in the "skins" folder.
Now, this only applies to the skins from our WEB site or via the auto-download in the game.
I am also assuming you are not using Vista as the operating system. All the rules for where things are located change with Vista.
Two questions on this method:
1. To download the skins.res file, do I need to have "download skins" checked in game.
2. After having got the skins.res file do I need to un-check "download skins" in game, cause right now, it just keeps downloading all the skins I have already downloaded from website.