New Discovery When you download a demo from the original Steam (www.steampowered.com), that demo usually comes with a preload of that game. (for example HL2 comes with the complete preloaded HL2). Instead of downloading many parts of a GCF/NCF maybe you should try out my idea. The preloaded full game (GCF) and the demo will be in your steamapps folder. Just use SteamClient or any other workable program to open them. There you go! That worked for me. I'm not sure if some of the games work or not.