I've tried all the settings that should work to associate jpgs with PP, but not of them are working. This is for PP 2018 in Windows 10 64-bit. Does anyone know of a work-around or something I might not have thought of so far? Thanks.
You don't say what you've tried but normal procedure (at least here) is to right click a JPG and choose "Open with...",From the menu that appears, select "Choose another app", then locate and select "Corel PHOTO-PAINT 2018" and check "Always use this app to open .jpg files". OK.Should normally take care of it.
Yes tried that, I can select the options, it will open fine then, but selecting another (or the same) jpg it opens with Paint3D, also tried going through Settings, selecting PP from alongside jpg but it doesn't accept it at all, just removes what was there and leaves a square grey + sign, Also tried another option through Settings -> Default Apps -> Photo Viewer. But all to no avail. I don't know where Paint3D came from and perhaps I could uninstall it, but I think that Paint, or MS Photos will just take its place.