I've installed a couple of free expansion packs for Rapture, including the old Muz3um pack. They're working fine on X2a Win 7. The updated installer that you linked to is for the free Cakewalk expansion packs. It takes the data and program files for the Cakewalk expansion pack and loads it to the correct place on your computer. This won't work for you since you want to use a different expansion pack. Just follow the instructions for the Minimoog expansion pack and you should be fine.