the galaxy forrge programs can be in ANY folder. on my win764bit i have my galaxyforge in a folder on the desktop, but the maps SHOULD go in the local settings galaxyforge folder
What is the advantage of this [method] over %programfiles%/stardock games/sins/galaxy and modifying the galaxy.manifest in the entrenchment directory? Does the Galaxy Forge folder automagically distribute maps? In practice I've found the Local Settings/Application data folder to be a lot less reliable 
DrGonzo