I hate to say this, but at some point, you may have to consider that this PC is just not going to work with Pro Tools. I hope I am wrong, but....
Have you/would you consider another DAW? Reaper is one option that is free to try and cheap to buy. Studio One is another(not as cheap as Reaper but very affordable) and Cakewalk by Bandcamp(Bandlab?) is completely free. All 3 of these options are less finicky than Pro Tools and extremely capable programs. Of course, if you want Pro Tools to be compatible with other collaborators, then it makes sense to keep trying
