Couldn’t for the life of me find and old cd/dvd drive to use but I do have an ancient laptop that has one. Will try creating a free as install cd. Which method would you use burning the iso to the CD? Windows built-in option?
I’m not sure why you’re jumping to a CD, the installer clearly boots already. I just don’t know if Rufus got rid of the GPT partitioning in creating your USB drive so I can’t say for sure that the computer seems to be already booting with PMBR+GPT on a USB.
That said, the installer image has PMBR+GPT so if you managed to write it in a way that preserves the PMBR+GPT, it would seem that your computer actually works fine with the PMBR+GPT.
I think it is worth a shot trying it with the CD seeing as we have not been able to think of any other theoretical reason why the partition tables are not setup correctly.
The partition tables are set up correctly though.