To be safe, I just reinstalled it again. Yet, even with the same files as you, it still doesn't run.
In fact, even without the patch, it doesn't run. Which is weird.
I was ready to dump this as a Windows 10 problem, but it's funny, I've managed to get the original Majikoi and it's A-1, A-2 to work on here.
It's just S that's doing this. Yet, the difference between the programs is that Maji1 and the A discs manage to actually become active apps (as NeXAS), while S stays as a background process.
Still, thanks for your help.