What exactly is your goal?
Testing our resistance in the willing to help you?
That's exactly what you are doing.
When you ask for help you must read carefully the answers and suggestions you get, and also the answer.
You were told in post #16 that your code is wrong:
File.Copy(File.DirAssets, tapecalc_en.txt, ProgPath, FileName)
it must be:
File.Copy(File.DirAssets, "tapecalc_en.txt", ProgPath, FileName)
In your last post, the error remains! You don't care about it !?
In post #13 you were asked to post your project so we could look at it.
You don't care about it.
So, finally what do you expect?
How could, should we help you when you seemingly ignore all suggestions.