BigSepp, before resorting to that, I would try a few things. Steam will default to installing the SH5 game in "C:\Program Files (x86)\Steam..." which does not work very well with most computers and the 'modern' Windows OS. If you do not have other Steam games, you can just uninstall Silent Hunter 5 and try to install it again, but when it asks you where you want the "Library" folder, direct it to a new folder you make yourself, such as "C:\Games...", then let the install routine do what it does. You will still find Steam in the Program Files folder, but the game will now be in "C:\Games \Steam \SteamApps \common \Silent Hunter 5" or similar.
After that, download and use The Wolves of Steel (TWoS) mod, and use the option for the Steam version of the game. You then go through the usual frustration of trying to get the Ubisoft account set-up properly. Just be sure and follow all of the options to use the game "off-line", which someone else would have to help you with, since it has been too long since I set my game up, and I have since forgotten how...
lol