I read somewhere around here that SH5 would be best installed outside your normal program files folder, although i do admit I cannot for the life of me remember where i found this so im not positive on it. Also, search around for the .exe patch for the game; from what i understand it fixes some bugs and issues with the game. Should be somewhere in the SH5 sections.
EDIT: Found where i read it, 3rd thing down:
http://www.subsim.com/radioroom/show...es#post1983456