Since many people are having issues with running this game on Windows 7 and later, and this thread is more or less active, I will bump this thread with a solution that worked on my Windows 7 64 bit PC.
The game originally didn't even want to launch on my PC, but using dgVoodoo 2 fixed that problem. Then it would crash when using the DirectX hardware mode after loading a level. That was fixed by installing the latest patch.
I have created a page on PC Gaming Wiki
with all the links and instructions: https://pcgamingwiki.com/wiki/Nocturne
Only "issue" left is that the intro video isn't being rendered, but you can simply skip it and watch it using VLC media player or something else. The memory warnings can also be skipped, or use Windows 98 compatibility mode if you wish.
dgVoodoo can also be used to enable antialiasing and anisotropic filtering. You can also enable bilinear filtering which makes the pre-rendered backgrounds less pixelated. Another thing that could be useful for some people is using dgVoodoo to increase color saturation, since the game is very gray-ish and often lacks color.
Alone In The Dark The New Nightmare and the Blair Witch games use the same engine as this game, so if you are having trouble with those or you want to enable some of the mentioned improvements you can try using dgVoodoo on those games too. I don't have those games to test.
Also it would be useful if someone would confirm this working on Windows 10, since I don't use it. Even if you don't have the game, you can simply try running the demo (I've put the links on the above PC Gaming Wiki page).