re missing notepad
Thanks for your help.
I tried your suggestions, starting with the OS repair install. Didn't fix it.
Then I imported the registry key from the 2nd PC, and although .txt file extension was shown in that PC, when I imported it into the 1st one it didn't fix it.
Then I looked at the link you provided about creating a C# program and decided that the simplest way forward was to create a shortcut in the Taskbar! So for the time being that is what I've done.
I have to admit though that I don't like the fact that I'm not able to solve the problem -these things get to me- I don't like the idea of a machine beating me, so I will continue to look for a solution.
If there is anybody else out there with a suggestion I am willing to try anything!
Many thanks again Kees.