You don't have to install Vista. This should run on all Windows OSes from XP through and including 10 with the latest updates. It will run on an nVidia GTX 6200 AGP (not too well now, mind you, but it runs), all the way through the latest / greatest PCIe cards with more VRAM than my current computer has.
How are you running the display at 144hz? What make / model of display are you using, and what is the connection type between the video card and the display? HDMI? Are there other choices in the games Graphic Options menu for lower refresh rates at a resolution that matches your display? If you right-click on your computer desktop, and choose the Windows "Display settings" from that context menu, after Settings / Display opens, do you see a drop-down for "Resolution"? Does it have "(Recommended)" next to the resolultion number? If you scroll down that page a bit, and choose "Advanced display settings", it will show "Desktop resolution" and "Active signal resolution". They are not editiable there, but should match. The actual refresh rate will be listed below those two. Back at the main Display page, if you choose the "Graphics settings" below that "Advanced display settings", you might have a choice for "Graphics performance preference". If that is set to "Universal app", try "Classic app" instead. You might also have several specific app names to choose from. SH4 is an old DirectX v9.0c app, and might benefit from a "Diablo II" choice, if you have that named... Otherwise, as THEBERBSTER has in his tutorials, it is rather straight forward.
A few more things to remember with SH4, is that this is not SH5, which has better water. Another thing is that the game is an old DirectX v9.0c game, and was intended to be run at 1024x768 on a 60Hz CRT at 30fps. It does look wonderful on my 1920x1080 27" ViewSonic, but I am running at 60Hz, and limited to 30fps (not a necessity usually). Also remember that when the sea is calm in SH4, it has a tendency to look a bit like it might do "jello" anyway. Try a mod, and see if you like that water better. Lastly, in your video, for SH4, the time of day of your start, the sea-state with no apparent wind, it's really not bad. There are some older vidz around, and I had one of my own a while back (probably never to be found again), and those are much worse than what you are seeing there. I've searched on ToobYu, and couldn't find one of the old examples...
