I must be blessed. I have recently installed the Steam Version of SH3 on my PC under Windows 10 and - so far, touch wood - have not encountered any problems. The only things I did were:
a) run the game directly from the SH3.exe file in Steam Library/Steamapps/Common/Silent Hunter 3 folder. I just right-clicked on the .exe and sent a copy/link to my desktop.
b)run the SH3.exe as an administrator.
I'm currently playing around with War Ace Campaign 5.1 (5.2 crashed on loading saves) with Optimised ARB Wide Gui 1920x1080 and Complete Sound for WACS.
I have noticed that sometimes SH3 Commander seems to crash my game near the end of loading a save, but loading that same save without going through SH3 Commander to run the game seems fine.
Sorry, but I have no explanation, or, sadly, help to offer those having problems with Steam's SH3, except the very basics of NOT installing in Programme Files (Steam Library should be a totally separate folder on your drive); verifying game files through Steam etc.
All the best with it.
