Arclight52, there are several possibilities. You are dealing with a game that is over 15 years old, and trying to run it on a 'modern' Windows machine. The first requirement is to install DirectX v9.0c with the game. The Steam and Ubisoft versions of the game usually start an install of that for you, as part of their game install routine, but with the disk version of the game, you have to select to install it and the codecs. The game needs the library files, and the DirectX v9.0c install does not overwrite any of the newer DirectX versions you have, but only supplements them.
Then there is the "Properties" settings of the SH4.exe file in Windows that have to be dealt with, since the game is not aware of how 'helpful' Windows can be. Navigate into the folder where you installed SH4, and find the SH4.exe file. If you do not have file extensions visible in the File Manager, there are two SH4 files, with the 2nd one being an icon file (ico), so choose the first SH4. Right-click on the file and then choose "Properties" at the bottom of the list. Windows 10 and 11 are slightly different with their Properties Windows, but you will need to click on the "Compatibility" tab in either. The various settings on that page will have to be experimented with to find what works best for your computer.
Win11:
Win10:
You may or may not need to set the Compatibility Mode. Depends upon your computer. You almost definitely need to set "Disable fullscreen optimizations". Your computer's User Accesss Control (UAC) setting will determine if you need to use "Run this program as an administrator". You almost always need to click on the "Change high DPI settings" button, and then click on the "Override high DPI scaling behavior..." tick box in the bottom half of the 2nd box, and set the drop-down to "Application. The upper half of that window is usually not needed, but on my one computer, I do have to use the Program DPI "Use this setting to fix scaling problems..." and set the drop-down there to "I open this program". On that computer (a laptop), the video card wants to zoom in on everything, not just the size of the icons or the size of text on the screen, but will attempt to scale the display where ever the mouse pointer goes... irritating. Anyway, you will have to experiment with those.
Lastly, if your intent is to apply mods in the future, you do not want to install your game in the Program Files folders. It would be best if you posted back with information on where you do have the game installed, what the source of your game is (disk, or Steam or Ubisoft download, etc) and what mod(s) you are thinking of using. Someone can help guide you from there.
