Open the folder, and then open a new explorer window and go to your C Drive/program files/lucas arts/foc
Manually go through the Alliance2.3X sub folders and copy and paste the individual files to the proper matching locations of the c/program files/lucas arts/foc folder locations - for this type of installation it is recommended that you back up your original FOC folder by just making a copy of it and renaming it.
After you copy all of the files from Alliance2.3X foder on your desktop to the matching appropriate locations of the c/program files/lucas arts/foc folder, the game will be fully installed, and you can launch Alliance Mod by normally starting up Forces of Corruption from the desktop short cut (you do not need to alter the shrotcut path or anythying). Remember that when you are copying the files over to the FOC folder, you are NOT copying them to the mods folder located in FOC, but the the main FOC directory sub folders.
This method allows you to only play Alliance Mod, and does not permit you the choice of playing other mods. I use this method of installation myself because I run Window 7 and the SMG mod launcher does not work with Win7.
If you wish to play original FOC game, or other mods, simply change the name of the FOC folder located in C/program files/lucas arts/FOC to something like "FOC_modded", and then place your copied back up of the original FOC folder back in the lucas arts folder. Whenever you wish to go back and play Alliance mod, simply remove the original FOC (the backup) to wherever you keep it for storage/later use, and change the name of "FOC_modded" folder back to just "FOC" by deleting whaterver extra text you used to change the name.
This process takes a few extra steps and might not be the quickest, but is really very very easy, and I have been playing Alliance mod for past 4 years like this, without any problems, game runs perfectly.
Hope this helps, and really, after playing Alliance mod, you may not really ever want to change back to any other mods wink
(Guide by Burnstrobe)