I did not want also to install VLC media player, which uses the same codec pack. I wanted to install only MPEG-2 codec. So, yesterday, I tried to install codec for only several video formats from K-Lite Codec Pack Basic v. 17.3 using the Advanced Installation Mode and it did not work. But, today, I install the new (released today) v. 17.3.5 using the Normal Installation Mode while accepting all defaults and it did work.
So the problem was solved. K-Lite Codec Pack Basic v. 17.3.5 is the software to install using the Normal Installation Mode, as the Advanced Installation Mode is a minefield requiring a really advanced expertise.
Thank you for the help.