Why is it that when opening a table in Cyrillic in UTF-8, Excel issues questions, but 866 Cyrillic DOS is normal?

Question

excel

Good evening!
I open a CSV file in Excel, but when I try to open it in UTF-8, it displays questions instead of words.
And in auto opening it offers 866 Cyrillic DOS, where the text is normally displayed.

How do I convert an excel file with 866 Cyrillic DOS to UTF-8?
Changing the file encoding in the editors did not help.

Answer 1

Add 3 "magic" bytes to the beginning of the file (or save as "UTF-8 with BOM")

Answer 2

https://www.hesk.com/knowledgebase/index.php?article=87