first google winrar, download & install it then unrar the galaxy forge to a folder
.check that you have the full .net v2.0 NOT THE compact(think compacted cars)
then run if you get a crash then update the directx9 to at least march 2008 and
make sure that you save the galaxy files in the program files galaxy and NOT the doc&sett/user galaxy (used ONLY by the map designer in game).
all this isassuming that you have at least sins 1.15 entrenchment 1.01.
at present if you want to play the map in entrenchment there is one more step
edit the galaxy.manifest file in the entrenchment folder adding the number of maps added to the top AND the fileName " your map name "'s to the bottom of the file then save
now explore your map/s in sins/entrenchment
harpo