It is partly personal experience, partly research and reflection based on my findings. I can't say more as, like everybody else, need to protect my privacy on here. But I know what I know, and I will share it on here.

That stuff with the Chinese characters on your computer sounds strange. What exactly did you do, and what was your previous configuration? I normally run a Western Windows system with Chinese language support installed and other special software for Chinese I have. Never had any problem.

You may perhaps make a separate post on that topic by providing more details as it also might interest other readers on here.

Not a tremendous amount I can say about it, Turnoi; only that I had just installed a KDE-Desktop-Environment, which I ddidn't know my way around in English even. I clicked on something with the aim of being able to temporarily change everything into Mandarin, so I could copy the characters onto a chalk blackboard i have; just to while away the time and practice writing characters. I am now thoroughly browned off, so will re-install the operating system, having wasted too much time trying to correct my blunder. Thank you, anyway.