If you don't manage to get this working, I suggest getting a cheap of copy of SH3 DVD from Amazon, eBay or somewhere like that.
I had problems with Steam SH3 (GWX3 installed OK, but LSH3 wouldn't install) so I gave up on Steam and ordered a disc version in good condition for less than the price of a beer. It's worth it!
I got this version, which installs SH3 1.4b (i.e. no patch needed) and NO Starforce!
https://www.amazon.co.uk/gp/product/B000FUCGDY/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1#
EDIT: I forgot to mention I am using Windows 7