So, I believe I have solved it. I used Disk Utility from the Recovery Partition and that works as expected. So, if you really need Disk Partition to work, boot into the Recovery Partition and use it there. There it works.
No, I need no help installing Windows. As noted in a previous post, once I swapped the MX300 with a Sandisk Ultra, Windows installed just fine.
No, I'm not a geezer who does not know what they're doing....but if you all want to do that forum thread, get to it, and all the best. But as for me, I'll pass.....