Hello again Aura.
Forgive the uncertainty of this, I've had a lot on my mind.
I tried the Refresh option. Within seconds of selecting it, the system said "There was a problem while refreshing your PC. No changes were made."
I tried again using a different route to the installation options. Sorry can't remember the details.
This time, in a window headed "Install Windows", I got the message "Windows could not complete the installation. To install Windows on this computer, restart the installation."
I don't have a note of what happened next, but the next thing I wrote was of a subsequent message "Setting up a few more things ... 2%, and it stuck on 2% for a very long time. During this time neither the keyboard or the mouse responded.
I switched the PC off, waited a couple of minutes and switched it on again. I then got the message "Preparing to refresh your PC", and according to my notes I got the same message (Preparing to refresh ...)again - presumably after the screen went black for a moment.
I think that I must have switched the machine off and on again, because my next noet says "Undoing changes."
Then I booted from Micrsosoft's Windows (8.1) 64 disc and selected refresh or repair - can't remember which.
That went well as far as I can tell. 183 updates were successfully downloaded and installed.
Are there any checks you want me to make now?