TL;DR, I've archived Project64 v.2.1 on the Internet Archive to restore my sanity.
Today, I took about 4 hours to earnestly research how to make Mupen64Plus work so that I could write a guide on the subject. It seemed promising at first, when I read that you could associate N64 ROM filetypes with Mupen64Plus.exe and use Windows to do the rest, but that fell apart quickly when I couldn't do that because I didn't know how to point the emulator to any of the plugins it needs to actually start games. So, I appealed to Newpipe, but the only tutorial was for a version of an M64P derivative that doesn't exist anymore, and the current version of that Github project requires top-of-the-line equipment to even run something as basic as Super Mario 64.
So, after bumbling my way through blind alleys, I decided to just cry "uncle" and put my preferred emulator onto the Internet Archive. It's probably already available there under a different user's collections, but I didn't bother to check.
Here's the situation, then. PJ64 v.2.1 has enough of 1.5 in it to run most games acceptably on the widest range of computers possible. Like I said in my other entry, I routinely ran 2.1 on Windows XP, and I've even gotten it to load on Windows 10. There are some artefacts, like shadows clipping through the floor in Super Mario 64, but I found that I could change graphics plugins to troubleshoot some of the problems I was having with Rareware games, like Banjo-Kazooie and GoldenEye 007. We still lose some surface overlays in Tooie, so if that's an issue for you and fullscreen gameplay isn't, there's always M64Py. In general, I'm confident enough in PJ64's ability to run on whatever machine you install it on that I'm changing my recommendation. Mupen64Plus is out, Project64 is in.
Just because we can't have this link in enough places: Project64 v.2.1.0.1 on the Internet Archive
--29 November 2023--