OK, we're getting somewhere.
For Win10, you'll need to either install the d3d8 dll file (available here) or a similar encoder for windowed mode. Just check the threads in this forum and you'll get a better idea which encoder you'll want.
The d3d8 dll will give you a full screen display BUT its based on the old 4:3 display format (your screen will look stretched a bit but its no big deal). The windowed encoders are also nice but sometimes a little tricky to set up.
If you use d3d8, just make sure you put the dll IN THE SAME FOLDER as dangerouswaters.EXE. If you can see the dll and the EXE icons in the same folder, you've done it right.
You'll probably need to edit some (display especially) options by changing the values in your dangerouswaters.cfg file. For Win10, right-click on the cfg file and choose "open with" and "notepad". You can check some other threads but basically search the cfg for "modeID=" and set that value to "3" then save.