No, the OS shouldn't matter, and really, the speed of the display shouldn't matter, unless it's too low. You should be right in the sweet spot for a computer... Fifi and Front Runner both have nVidia
Inspector set-ups that you could attempt to apply, which is where I was getting that "Diablo II" comment from, since they use that as a reference in Inspector. Another thing to try, though I don't know if you would see a difference in the Stock game, is to use a LAA (Large Address Aware) aware applet on the SH4.exe file, so that SH4 is able to address more than 4 gig of RAM. It was written to that spec, but at the time, was not "enabled". For reference to that and Windows 10, see CapnScurvy's thread
Windows10; Large Address Aware; SH4 Install. It might be that it needs that RAM, especially if your computer maybe has a bit of "background" apps running...