When I compared Hitman: Codename 47 running on my Windows 10 gaming PC and a Windows XP machine I noticed that they look completely different in subtle ways. At the same resolution on both machines, I found that on Windows 10 the game looks much more artificial, sharper, less realistic, there is less contrast, and the colours just look wrong and dull. Running the game on Windows XP, the game looks different because there are effects in game that you can't see when you run it on Windows 10. The game looks more impressive graphically, and it seems like the game is running as though it is meant to be seen for that time, in 2000. Much more contrast, more accurate colours, softer edges, and the game just looks like it is supposed to. I compared the mirror effect in the bathroom in both instances of the game, and on Windows 10 the mirror reflects Agent 47 incorrectly, and his model looks a bit transparent, compared to Windows XP. The tiles on the bathroom floor in Windows XP reflect light in many different directions, compared to Windows 10, where they only reflect in one direction. Not just with this game but all games I've tried from the 2000s just look better running on the system they were designed for. But when you run the same games on Windows 10 they just look wrong and artificial.
I've been trying to analyse what the reason behind these differences are, and at first I thought it had something to do with the version of DirectX. Windows XP runs DirectX9, and Windows 10 runs DirectX12. Windows 2000, which the game was originally released for could run the game on DirectX9. DirectX9 in Windows XP is the DirectX version used for the game originally compared to DirectX12 in Windows 10. I read on a forum somewhere that the features used in previous versions of DirectX are not always supported by newer versions, and some features are dropped with every new version. Maybe DirectX12 is missing some features in the DirectX which the game relies on? Microsoft support for older DirectX versions for 3D applications like video games has also never been good. Is this difference in DirectX versions on both OS's the reason for the difference in graphics?
I've been trying to analyse what the reason behind these differences are, and at first I thought it had something to do with the version of DirectX. Windows XP runs DirectX9, and Windows 10 runs DirectX12. Windows 2000, which the game was originally released for could run the game on DirectX9. DirectX9 in Windows XP is the DirectX version used for the game originally compared to DirectX12 in Windows 10. I read on a forum somewhere that the features used in previous versions of DirectX are not always supported by newer versions, and some features are dropped with every new version. Maybe DirectX12 is missing some features in the DirectX which the game relies on? Microsoft support for older DirectX versions for 3D applications like video games has also never been good. Is this difference in DirectX versions on both OS's the reason for the difference in graphics?