Hrm. So, I found a couple entries. There were a few entries that didn't allow me to delete them - said "unable to delete" or something, even with running as an admin and running normally. While the game was uninstalled on all drives.
Is there any straight-up archive of the TSLRCM files themselves instead of the installer? Or one that lets me pick an install path? I'll keep monkeying around. Worst-case, I'll just try installing it on a laptop and...I dunno, copying and pasting the whole game directory onto my desktop one. That's probably a terrible solution but it's the only one I can think of lol.
EDIT: attached image.