OK, this did not help because I already tried to clean registry myself,
and got rid of all entries like ’emeditor’ and ’emed’ related to EmEditor.
I deleted relevant keys as well.
I decided to install v7 RC6 on top of the v6.004 free and in the same folder ;-)
Of course, I received the same error, BUT now I have v7 RC6 running :-D