Windows 10 does not like it when you play 10 year old games on it... Did you by-chance, install the DirectX v9c when offered the choice with the game install? If not, run the game install again, and use the older version of DirectX. The newer versions of it do not have the full library that Silent Hunter needs.
Also, do NOT install the game in the "C:\ Program Files (x86)" directory. If you've already done that, un-install it, and when you re-install, overwrite that "Program Files (X86)" portion of the path with a <Delete> button press, and just leave it at "C:\Ubisoft...", or whatever you want to make it. Windows "protects" the Program Files folders, and will restore any altered files it finds in there that were not authorized through the proper Windows API...
