GreekMantanis, SH5 is just like SH3 and SH4 on the 'modern' Windows OS, in that the game was designed with WinXP DirectX v9 internals (the game engine). In that regard, you have to tell Windows not to help with the game's display. To do that, you need to navigate to the game folder where you have SH5 installed. Find the SH5.exe file, right-click on it and choose "Properties" from the bottom of the list. Then click on the "Compatibility" tab and then change some of the settings. Depending upon your computer, video card and display, you might have to change one, or several of the settings. Win11 is similar to Win10 in that regard and SH3, 4 & 5 are basically the same. Here is a picture from SH4 on my Win11 laptop, and the choices I had to make to get SH4 displaying properly:
Your computer might require the same, but most likely different settings. That upper "High DPI Settings..." Window comes up after you click on the "Change high DPI settings" button of the window below, which is the actual "Properties" window. You might not need the Compatibility Mode change, and you might not need the Administrator setting tick mark, but you almost certainly will need the "Disable fullscreen optimizations" ticked, as well as that "High DPI scaling override" with "Application" set from the "Change high DPI settings" button. On my laptop, I had to click that upper button on the "High DPI settings for..." window, since the computer wants to "scale" everything on my display to 125% for whatever reason, and when it does that with the game, some of the game's interface goes outside the displays boundary, of course...
Anyway, try those settings (less the "scaling" change) and see what you get.
If you are going to eventually use the TWoS mod, and you installed the game to the "default" path, you are in "C:\Program Files (x86) \Ubisoft \Battle for the Atlantic..." or whatever the name of the SH5 folder is (I don't have it installed on this computer), Windows will rollback any alterations attempted in that folder. You will have move the game to a folder outside of a Program Files folder. If you create your own "Games" folder on the C drive and then install to that folder, any modding attempts will function correctly. vdr1981 mentions that in a pdf that comes with his mod.
