you must be able to unpack a file using 7zip you must have SH3 installed and NOT have modified the game in any shape, sort or form The following instructions presume that you comply with these prerequisites: And this works with every Windows-version! I thought I'd give you a complete set of easy-to-follow instructions on how to get STEAM's SH3 to run with GWX and further mods, even despite the fact that Steam doesn't support mods for SH3.