As Ivan says, it looks as if my problem - myCNC crashes on Windows 10 shortly after it starts - was due to a graphics driver problem. This, perhaps, makes me look even more silly than usual. I suspect that what happened is that I have been running Windows 10 on my workshop machine for a while, and I am pretty sure that I had installed the graphics driver from the nVidia web site. However, a couple of months ago I had problems with Win10 and reinstalled. Win10 appears to have a bundled graphics driver that works fine with my nVidia graphics card and I have not seen any problems with it - until myCNC was installed. Unlike most Windows software which uses DirectX graphics protocols, myCNC uses OpenGL. It seems possible that the default bundled Win10 graphics driver works fine with DirectX, and may even work to some extent with OpenGL, but does not fully support OpenGL. The debug software that the PV engineer ran on my machine showed that Windows driver did not properly respond to OpenGL requests, but as soon as I installed the full nVidia driver, all worked fine.

There is also a simple workaround to the "save configuration button is off the screen" problem. There is a "minimise window" button available within myCNC (not the Windows-supplied button in the top RH corner of the window "frame"). Click this to minimise, then click on the taskbar myCNC icon to maximise it and the window is back in the correct place. This is a temporary workaround as I am told that the engineers are working on a proper solution to this, as well as tidying up a few loose ends on the Windows version.

I am now happy to run myCNC on Windows. I do have a few more problems but those are pretty detailed issues around macro writing and I shan't bore people here (if you have even read this far) and I shall be asking questions on the PV support forum, which is the right place for them.