Getting it running was pretty straight forward. The installer has to be ran in compatibility mode or as admin. Same for the game. This is typical of 95/98(se)/2k/XP era games since those operating systems didn't bother with checking user authority. I used to play another game that I can't run in Windows 10/11 because of all things, direct X being too new. It ran fine in Win 7. I think it was call Artificial Girl. I've moved on to Koikatsu so it's a non-issue now.
Normally if a file isn't encrypted, I can pull it apart with a simple c# program. I made a drag and drop extractor for ARC files in like 20 mins. But even trivial encryption stops me cold if there isn't a decryption tool. I've just never been able to wrap my head around encryption. It's annoying too. I love when I check an RPG Maker game and it's not encrypted. Same for Ren'Py and other games. I get the whole; protect assets, but if someone did steal assets, they'd get found out pretty fast. (I hope)