I suggest that you update your Account details (click your user name at the top right of the forum) so helpers always know what Excel version(s) & platform(s) you are using as the best solution often varies by version.
IF you have Excel 365 with the new Dynamic Array functions, this would be another way. With limited testing this also seems to be significantly faster when dealing with large ranges (like whole rows)
=IF(COUNTA(UNIQUE(FILTER(1:1,1:1<>""),1))=COUNTA(1:1),"No Dup's","Dup's")