Alright, so I originally posted an inquiry with the exact same name about nine months ago, all the way back in January, here is a link to the original discussion:
A lot has happened since I originally posted this topic, however, the biggest thing is that I've done several upgrades on my main system, including replacing the motherboard and CPU wholesale. I was planning on capturing footage of this game for my YouTube channel, but now I've hit this same brick wall yet again, except this time, nothing I've done has solved the problem. I'm at a complete loss on this now, as the methods of uninstalling and reinstalling the game and manually editing the hex value to not require the disc no longer seem to work.
I honestly don't know if how I got it to work last time was a fluke or not, but it stayed working for months until just today. If anyone has any advice that hasn't already been covered on the main wiki and in my original post, I'd very much appreciate it.
Thanks.